Well it happened. PG&E has dropped the facade of necessary rate increases because of system upgrades, and they have come out and said what…
Before I could install a solar system I needed to have a new roof done. I could have probably gotten a few more years out of the asphalt roof, but I didn’t want to rip off the panels to redo it. So after a few months of quotes and scheduling I had a local roofing company come and replace it while I continued doing research on exactly what solar system I wanted. The cost was around ~20k.
Batteries Are Heavy
Once all the equipment was delivered, I had to figure out how to actually move the batteries into their final resting place. They weigh 300 pounds, and though they have some ropes to help you break them out of their shipping containers, that didn’t work for moving them. I settled on using some moving straps, which worked great. Two people would lift with the strap, while a third helped position the battery by the wall.
The batteries themselves are mostly supported by the feet, with the wall attachment used to stop them from falling over and to hold the inverter (which is considerably lighter than the batteries).
You’ll note I used Unistrut to mount the batteries and inverter. This was after I had already started building it with wooden 2x4’s, and then read in the battery installation manual to not use flammable materials. Woops. Always read the installation instructions. At least I didn’t get too far before I realized my mistake.
One other thing I will mention is I didn’t realize I was sent the outdoor version of the EG4 batteries until I had already mounted them. This shouldn’t be a problem because I was installing them inside the garage, but the cable shroud was for the indoor version and they are not interchangeable. A quick call to the seller and they shipped me the proper shrouds.
It would have been much more of a problem if I was sent the indoor batteries and needed them for an outdoor installation. Luckily, the electrical specs of the batteries are identical, they just have slightly different housing. The takeaway here is to really make sure you sent the proper equipment before you install it.
And even though the equipment I was using was outdoor rated, I installed the inverter and battery in the garage for a few reasons:
- The inverter is outdoor rated, but is supposed to be shaded. I would have had to build an overhang to shade it in the afternoon. There is also a small shed that would have had to be removed where it would have been installed.
- The garage has less extreme temperature swings.
- It is more protected from purposeful and accidental damage.
Of course, the main con is the system takes up room in the garage. Some shelves that used to be there had to go. I also had to install a heat detector in the garage that is networked with smoke detectors in the house because of batteries inside the garage.
Wiring is Simple When You Have Someone Else Do It
In theory, wiring the inverter and batteries isn’t too difficult. But it is not what I would consider trivial either, and I am far from an expert of electrical work. Now is a good time to mention I didn’t do this alone. My dad has a lot of experience with electrical work and did all the wiring on this job (don’t worry, I held the flashlight). Also, when I say “I” did something, it really was “we.” I think this is where many homeowners would probably outsource because dealing with 240v can be daunting if you have never done it. Lucky for me my outsourcing only cost me lunches.
The manuals of the inverter and batteries are very detailed and provided all the schematics for how to wire everything together. It is extremely important to follow them exactly. For example, it is imperative you use wire ferrules for all the connections inside the inverter to make sure each connection is solid and won’t come loose.
Here is a simplified overview of how the core components connect together.
So battery 1 is the “main” battery that is hooked up to the inverter. Batteries 2 and 3 each connect to battery 1. Here are some close ups of the sides of the batteries.
When this was first wired up, I had no solar panels and the inverter essentially just acted in pass-through mode. The only time the batteries would kick on is in the event of a power outage (though this has yet to happen — PG&E is generally pretty stable in this area, especially in the winter. Summer is another story though).
I could have used the batteries to “peak shave,” where I charge them during low rates and discharge them to load during high rates. I didn’t really care to do this that much though because my end goal was to have my panels charge them completely anyway. Also, I couldn’t figure out how to do this in the EG4 software. User error, no doubt. I’m sure I could have done it if I called support though, but I didn’t care enough to follow up.
Lastly, this is also when I installed the new subpanel. I also took this opportunity to run a new dedicated 20A circuit to my server rack, since the rack was right next to the new subpanel.
Voltage Issues
I did have to call support for a voltage issue I started seeing as my batteries sat around for a few weeks while I worked on getting my panels installed. The battery state of charge (SOC) stated that it was at 90%, but I was getting a low voltage warning on my batteries.
After calling Signature Solar, they mentioned this can happen if your batteries sit around for a while without charging or discharging. They had me re-calibrate the SOC with the voltage by having the inverter treat the batteries as lead acid for a few charge cycles. By this time I did have one string up and running, but not enough to completely run my loads and charge the batteries.
I had to manually change the charge and discharge settings every couple days to get the batteries to fully charge and discharge (100% and 20% respectively). After cycling my batteries 5 times over a couple weeks my batteries have been running smooth.
Only Make That Mistake Once
Now’s a good time to go over the mounting solution I used: Ironridge. My solar planner put in my system and roof specs into some software, which kicked out a bill of materials (BOM) I could give to my local Platt. That BOM ended up being a little bit off but was close. I had to order a couple more bolts and also returned a few rails that I didn’t end up using. The Ironridge system wasn’t cheap (I think around 2.5k for all the pieces), but it is extremely high quality, and this is something I want to last for years.
Using a chalk line, I marked the rafters I would be using as the mounting points for the rails. Ironridge does sell a model that allows you to not have to use rafters, but I opted for the rafter model that uses less screws.
Once the rails were installed (making sure to seal everything with outdoor rated silicone), I made my first mistake (related to the panels) that would have to be corrected later: I didn’t plan out all my wiring and run it before actually mounting the panels. Things like the wiring to the Tigo TAPs and ground wires. Why does this matter? Well, it is code that no wires touch the roof, and it is a huge pain to fix it afterwards. I ended up having to take some panels back off to fix it, but not all of them.
On later panels I ran the ground wire and communication cable for the TAP, as well as prepped each panel with cable clips as they were installed. It is much easier to cable manage as you go instead of having to fix it later. Luckily, I only made this mistake on the first string.
Wiring the First String and Optimizers to the Inverter
Each panel in the string is wired to a Tigo TS4-A-O optimizer, with each optimizer wired to the next one in the string. My first string (south facing) has 12 panels. I then ran a positive from one end of the string and the negative from the other end into a junction box (pictured above). Inside the junction box they are connected to metal clad (MC) cable, which runs through the attic to one of the inverter’s MPPT hookups.
The reason for using MC cable + junction boxes are so I didn’t have to work with metal conduit. I also think it ends up looking a lot nicer because you don’t have long metal conduits running all over your roof. The downside is you have to crawl around in the attic to route your wiring. The end result looks pretty great though.
Aside the positive, negative, and ground wires, you’ll notice there is also a white cable coming out of the junction box. That is for the TAP. The TAP provides the avenue for wireless communication between the CCA and the optimizers. This is critical because when the ESTOP is pressed, your panels need to turn off for fire safety. It is also wired into the inverter/batteries. This means at the press of a button all solar, inverter, battery, and electrical loads are shutoff.
Each TAP is daisy chained from the previous TAP. Tigo has excellent documentation on how to wire up the TAPs and CCA.
Tigo Software Setup
The Tigo software is pretty straightforward. You add information about your panels, inverter specs, and the serial numbers for your CCA and all the optimizers. Then the system scans for the optimizers, which you can associate on your system view so that the layout matches the panels on the roof, like this:
I did run into a weird issue where Tigo’s system was reporting missing or incorrect types of optimizers. I called Tigo about this and they recommended waiting a couple hours. Sure enough, a few hours later everything reflected correctly in the web and mobile apps.
The last thing to do before I could start using my system was to make sure my ESTOP was hooked up to the CCA and my inverter. I followed some tutorials on YouTube to do this.
Now I was ready to start charging my batteries and running my load from solar.
EG4 Software
Similar to Tigo, the EG4 software is pretty straightforward and defaulted to a lot of reasonable settings. These are a few settings I had to change:
- Battery type to Lithium
- PV input mode to however many MPPT hookups I was using
- Off-grid mode to enable (temporary until I had PTO)
Based on manufacturer support, I setup my batteries to charge to 100% and discharge to 20%.
I did have to do a firmware update for the inverter. You can use the mobile app to do this, but I highly recommend just upgrading firmware through the web UI — it’s much more reliable. I kept having issues with the mobile app firmware update failing. My understanding is that is more useful for locations where you have no internet access. Updating the firmware will cycle the inverter and cut power to your loads for a few seconds.
I also had to update the firmware for the screen on the inverter, which required using a USB drive. Again, I ran into a few issues here but eventually got it working by using an old USB 2 drive with FAT32. This had to be done because after the inverter firmware update, the screen was displaying incorrect wattages. The screen firmware update fixed that. I’m not quite sure why the screen requires a local firmware upgrade, versus the inverter itself that can be done over the internet. Here’s what the screen looks like:
You’ll notice in the above screenshot the inverter is in “Backup Power” mode because I have offline mode enabled, so as to not bleed power back to grid. It would also look like that in the event of a power outage. Once I got my PTO I was able to turn that setting off and it now looks like this:
Power can now flow between solar, my batteries, my loads, and the grid as needed. In my case my power flow is such:
- Solar powers loads
- Excess solar goes to batteries
- Once batteries get to 100%, excess power is exported
- If solar is not enough to power loads, add supplemental power from batteries
- If solar and batteries are not enough to power loads (rare), import supplemental power from grid
- Batteries will then discharge to 20%
- Import power from grid if batteries become depleted
I’m Getting Pretty Good at This
You may also be wondering how I got all the panels on the roof. Well maybe not, but I’m going to tell you anyway. My dad had a sweet portable set of stairs. This made getting the panels up on the roof much easier, as using a regular ladder would have been a nightmare. I’ve seen some folks use a winch, but we didn’t end up needing one.
The first of the other strings is an east facing string that consists of 12 panels, split across two sections of the roof. That means I had to use junction boxes to connect them, so as to not have any cables running across the top of the roof (in metal conduit). Aside from that, and also running the wires correctly during installation this time, the east facing string installation went well.
The west facing string is a little different because it’s actually two strings run in parallel: 14 panels divided into 2 strings of 7. Similar to the east facing string, I had to jump one of the panels through the attic to another section of 6 panels to make it 7. Then each string of 7 connect to the inverter using separate MPPTs. These MPPTs are actually the same internal circuit, but allow up to 25 amps (the other MPPTs are only 15 amps). You can see the visualization of this in the Tigo image above: strings A, B, C, and D. C and D are run in parallel and show up as one string in the EG4 software (PV1).
Inspection Time
Once everything was up and running, it was time for prepping for the inspection. This means tidying everything up, installing warning labels, etc.
When the inspector came out he found the following issues that needed to be fixed:
- Missing site diagram placard at MSP
- New grounding rod required at MSP
- Interconnect heat detector with smoke detectors in bedrooms / hallway
- Add labels every 10 ft for DC cables in attic
- Add a spring to a door into the attic from the garage (fire safety)
- Fire caulking where DC cables exit the attic into the garage
- Some cable management on south facing string (the first one we didn’t cable manage correctly the first time)
A week later and those issues fixed, the inspection passed! What a relief.
Permission to Operate (PTO)
We finally arrived. The final hurdle: PTO. I will mention at this time the system is fulling operational and powering the house, I’m just unable to dump excess power to grid to get paid (at least a little…). At this point I was generating maybe between 40–50 kwh, depending if the AC kicked on at all on a warm spring day. But I could see my batteries were charged often by 12–1 PM, and my solar panel output would drop from 10–12 kw to only ~1.5kw to run my loads.
After I figured out where to start the PTO application process (it’s not the regular PG&E site, it’s actually https://yourprojects-pge.com), I started the application. Here’s where I ran into another roadblock: the application started asking me questions I had no clue how to answer. So back to my solar planner I went, who was able to recommend me someone who specializes in solar applications to power providers. I had the option of paying her $300 to do the entire thing, or $150 for only portions I couldn’t figure out. I opted for the $300 fee and she was able to get my application submitted in a couple days.
A week later it was approved. The only thing left was to disable off grid mode. The system then started exporting power once the batteries were full.
On a nice sunny day I now yield around 85 kwh. That number of course depends on temperature, cloud cover, and the time of year. But for now, my electrical bill is completely covered and then some. Here is the first couple weeks of electrical usage for May, with export enabled:
That tiny bit of power import on the 9th was because I accidently turned on quick charge for around 10 minutes, which started charging the batteries from grid. Woops.
I have noticed that PG&E is reporting a little bit of power draw, even when I am running from solar/batteries. The inverter is reporting similar (albeit a little bit lower than what PG&E says). We’re talking maybe ~1 kwh, which is fine considering I’m often exporting 30–40 kwh of power to the grid.
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Comments
I’ve been running a solar microgrid on my coffee farm for the last 7years. We started with a few golf cart batteries and 4 panels, these days we’re powering 4 houses, 7 cabins, water extraction, treatment, and RO processing, campus-wide fiber network and switches, path lighting, security systems, and a small server rack.
We’re running 6 inverters on our primary system in a three phase configuration, 35kw of panels and 160kwh of lithium iron batteries. About to add an additional 20kw of panels and a test bank of LiTo cells.
Our panels are a distributed set of rooftop mounted panels on various buildings, which also serves to shade the rooftops reducing cooling loads.
We still have to run a generator to supplement charging on dark overcast days, but it’s typically about 100 hours a year. Hooping to get that running on biomass eventually.
It’s strange to me that people in rural areas pay for electricity. It makes no economic sense, at least here in the Caribbean.
> It’s strange to me that people in rural areas pay for electricity. It makes no economic sense, at least here in the Caribbean.
This comment was very confusing until I read the second sentence. Electricity prices in the Caribbean are very high, and I can only imagine that rural areas are even worse.
Where I’m at in the United States a typical electric rate is around $0.10/kWh. Paying that nominal amount and avoiding the need to service additional equipment and deal with backup generators is an easy decision.
By Moto7451 2025-05-2113:48 You’re in a good part of the country for grid power. I’m in Georgia where the typical rate is about 14 cents but summer rates are more like 18. Summer rates aren’t captured in this EIA chart but you can see the whole country. With summer rates and high energy use for cooling and dehumidification it’s a 7-8 year payback for a 13kW DC/10kW AC system.
https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...
By nullpoint420 2025-05-2113:426 reply I’m jealous. Where I live in California the off peak rate is $0.32/kWh and peak rates are $0.58/kWh.
Rural area power co-op member here - flat rate 24/7 for residential is .13/kWh. Businesses/farms can get down to .10/kWh if they qualify.
They proposed to update it to .15 so they could trim trees around the lines a little better, but it got denied by the co-op members as unnecessary.
By baby_souffle 2025-05-2114:282 reply > They proposed to update it to .15 so they could trim trees around the lines a little better, but it got denied by the co-op members as unnecessary.
Pge felt the same way and it did t turn out so well for them. I hope your coop is never found to be at fault for the next record breaking fire…
By Loughla 2025-05-2114:44 So the increase was to buy spray equipment to attach to a helicopter. And a helicopter. One of the co-op ex-board members' son recently moved back to the area and had his license. . . It was a shameless cash grab by that family and was rightfully voted down by a wild majority of the co-op members. Every member of the board was replaced within 2 years of them proposing the increase as well.
They currently keep all the lines clear via bucket trucks, and when they spray, they use ATV's and trucks. It takes most of June to spray all the lines, but they get it done easily.
The actual physical infrastructure has been replaced almost entirely in the last 10 years through federal and/or state grants in combination with income from power charges.
Also, these are just fundamentally different entities. PGE is a private entity that operates for a profit. Our power company is a co-op owned and run by its members. If they have any profit at the end of the year (once infrastructure improvements and safety net investments are paid for), the money gets paid directly back to the co-op members. It's a WILDLY different incentive structure.
By coryrc 2025-05-2116:48 Not every place is built in a dry forest which traditionally burned regularly but the current infrastructure is built around never burning. The only risk in, say, Michigan, is the power going out at inopportune times.
By bilbo0s 2025-05-2114:12 If that's considered high, I'm just not going to say what it costs in the Caribbean.
At least where I was.
By supportengineer 2025-05-2118:05 I'm in the Bay Area - Off peak is 0.44 and peak is 0.48
Separately for "clean power", Off peak is 0.13 and peak is 0.17
So that's a combined 0.57 and 0.65
By ComputerGuru 2025-05-2115:151 reply Taxes and supply charges are what take it from cheap to expensive in Illinois.
By robohoe 2025-05-2118:07 Yep, and we have 5 nuke power plants in vicinity
By horacemorace 2025-05-2117:371 reply Doesn’t that sort of rate make the payoff for a solar system install just a few years?
By hn_acc1 2025-05-2121:44 Yeah - even with PGE trying their best to screw over solar customers in the last few years, I figure we've at least gotten our money back in ~15 years of owning a ~4KW system. Something like 75 MW generated in that time, assuming the inverter is more-or-less correct. At this point, doesn't make any sense anymore, since they only credit you like $0.1 and charge you $0.6 (I haven't looked too closely at it) - you'd have to generate 5-10x your consumption to mostly offset it.
We bought ours in '10 to offset high AC use in the summer - we were paying $1000-1500 a month for 2-4 months in the summer. The first few years, our "year-end" balance was < $1K (we just paid minimum payments the rest of the year), so I figure we easily saved $2-3K/year in those early years, and after the incentives in those days, we paid ~$14K, so maybe 7 years to pay it off. Our year-end balance was more like $3K the last time, and I think we're still producing 80-90% the same power, but PGE keeps changing the plans around. At this point, I'm interested in upgrading our cells from 300W to 450W, but I'd only do that with a battery system that also stores energy so that we could go more or less entirely off-grid. But probably need a new roof first..
By w10-1 2025-05-2118:09 > I’m jealous. Where I live in California the off peak rate is $0.32/kWh and peak rates are $0.58/kWh.
My California rates are .50/63 off/on peak
"Jealous" is not the term I'd use...
By testing22321 2025-05-2210:531 reply I’m in a mountain town in BC Canada and pay $0.13/kWh. My 7.8kW solar system cost me $0 out of pocket after incentives and an interest free loan. It’s making ~$1000 per year of electricity, so we’ll just put that onto the loan for the next 8 years instead of paying it to the power company. Then for ~25 years after that it will make me $1000/year. Free money.
(The price of electricity is already pre-approved to increase 5% a year, so actually my savings will be more every year than the year before)
Solar can be worth it even when power is cheap.
By Scoundreller 2025-05-2221:521 reply Why pay off an interest free loan?
By testing22321 2025-05-239:12 It has to be paid off in 10 years.
In Quebec, I'm paying $0.069/kWh or USD $0.05/kWh (hydroelectric, so already green), so it's hard to make a case for solar.
> hydroelectric, so already green
Not so fast. Zero emissions, yeah. But they have damaged the habitat for some bird species.
By singleshot_ 2025-05-2121:343 reply Would love to see your analysis of Thanksgiving
Feral cats kill 2 billion birds a year, FYI the green energy kills birds thing is a right wing talking point designed to distract and delay. All human activity kills some nominal number of birds
By RajT88 2025-05-2122:19 Indeed. They care about the environment when pretending to do so lets them fight against things which are actually good for the environment and bad for the fossil fuel industry.
By gosub100 2025-05-2212:18 Whataboutism arguments kill 2 million discussions per year by avoiding refutation of the central point.
By tonyarkles 2025-05-2120:03 I'm in the Canadian prairies and we pay a similar electric rate. It's funny though...
> avoiding the need to service additional equipment and deal with backup generators is an easy decision.
We've got a house in a very small town (pop. 100) and there are solar panels on a ton of the houses there. I've asked a few people about it and it's 100% for grid redundancy. Sure, they save a bit of money on their power bill, but they're basically using the panels and batteries as an alternative to a backup generator. Winters are quite cold here and having enough power to run the natural-gas-fired furnace and a few light bulbs is a huge win when the power inevitably goes out. Lots of people have small generators kicking around too (like the Honda EU2200 that RV folks love) but the solar install has seriously cut down on the need for those.
By jorblumesea 2025-05-2115:401 reply $0.10 kwh is low for most of the US. Can I guess.... Western state or PNW?
By entropicdrifter 2025-05-2116:081 reply Over here in PA I pay $0.095, so nine and a half cents, per KWh for electric supply, but then I pay that same amount for transmission, so it's functionally 19 cents per KWh, but maybe the person you're replying to isn't counting transmission fees?
Similar here in Maine under CMP. Something like 12.5 cents/Kwh, but with the delivery aspect factored in it's basically 28 cents/Kwh.
I always assume when people on here are talking their 'rates', that they are usually NOT factoring in the delivery fee unless stated.
But maybe some places are just really THAT cheap.
By philipkglass 2025-05-2118:38 I pay 11.6 cents per kilowatt hour inclusive of everything (taxes too). My household used 647 kilowatt hours in April and the bill for the month was $75.02. The per-unit charge neglecting taxes and delivery is only 7.4 cents. This is in Washington state.
I don't know why anyone would not include the "delivery" fee, I think it really is that cheap in many places in the US.
Here in NYC the "supply" charge is much less than half of the total bill. If I add up all the fees and surcharges and taxes etc, the total ends up around 35 cents / KWh, which I thought was rather high until I heard about California ...
By devilbunny 2025-05-2216:42 I pay around 10 cents per kWh in the southern US; we have a nearby nuclear plant. We do have a base fee just for the meter, but no separate transmission fee. My in-laws in Texas have an open market for generation but pay transmission separately.
By jorblumesea 2025-05-2118:49 why would you not include the transmission? residential customers just pay one bill and that's including the lines, maintenance.
In western states such as Oregon, Washington, it is actually 0.12KWH including transmission.
How has your experience been with the lithium-titanium-oxide batteries? Everything I read makes it sound like the optimal solution for safety and long life, but it doesn't seem like they have displaced other battery chemistries very much.
By K0balt 2025-05-222:30 I’m excited to try them too… I’ll get back to you in 5 years lol.
What is your recovery plan in the event of a hurricane?
I'm not fond of high electric rates, but in addition to generation those rates amortize and distribute the cost of storm recovery. A home or business with grid-tied solar pays interconnect fees for the option to get paid back a little for excess generation, and the option to decide to switch back to 100% grid power if a storm damages the on-site panels.
> those rates amortize and distribute the cost of storm recovery
Not exactly when it is a farm out there away from a town.
My experience is from a different era (90s) and a different kind of farm, but I spent a bunch of summers in one, which had power outages whenever the monsoons picked up.
The trouble was that there was a single line feeding the farm from about 6km away, so if that went down a single farmowner complained - the rate payers who were in a denser urban area always got priority, because there were 600+ people who shared a transformer.
The generator ran a lot when winds knocked power out, but the generator only ran when there was a big power need like running the well pumps or one of the winnowing mills. Even the winnower had pedals, because work doesn't stop.
Every bathroom had a light with a 30 minute battery in it, which came on when the power went out - I guess if they had LEDs those same batteries would be 6 hour lights.
They would have killed for solar + storage, because shipping fuel in for the generator was one of those annoying things you had to keep doing over and over again.
By p_j_w 2025-05-2118:06 >The trouble was that there was a single line feeding the farm from about 6km away, so if that went down a single farmowner complained - the rate payers who were in a denser urban area always got priority, because there were 600+ people who shared a transformer.
The urban rate payers also subsidize the rural ones, so it makes sense that they'd be front of the line.
By devilbunny 2025-05-2216:48 I would have thought an isolated farm would have had propane on site - likely more than one tank.
I don’t worry about outages much in my current home because the main line to ~1000 houses goes right past me, and I’m fed straight from it. If I’m out, it’s a very high priority line. Worst ever was about two days. It helps that our worst storms are usually in spring, so weather is mild.
By rz2k 2025-05-2114:33 After a hurricane, the plan might be to help neighbors charge their phones, or sell electricity to telcos to power their networks switches and cell towers.
I think I am much less remote than the poster, and I can easily lose power for a week or more after a winter storm. Considering that they already have generators on site that can manage the full load, they probably have much better up time than the utility electricity provider.
By K0balt 2025-05-222:34 All underground infrastructure or in concrete utility huts. Powerplant is concrete, no flooding issues due to excellent drainage of the area.
We can run on generator to charge the batteries for about 2 weeks on the fuel we keep. Other than that, we rebuild what isn’t broken and later buy more panels. Most of our mounts should be good to about 150mph, but trees also fly so?
Good news is we can buy panels here about $120 for a 500 watt panel.
Also we have some geographic protection from the full brunt of a storm , as we are in a mountainous eddy zone that typically sees about 30 percent of the coastal and mountaintop wind speed when a cyclone passes nearby as they frequently do.
By MostlyStable 2025-05-2116:062 reply For the US, the entire user base helps subsidize rural customers. I have recently had the thought that I'm curious how this subsidy compares to the price of creating local micro-grids for rural communities. Especially in places like California where it is long distance power lines running to rural communities that have started several major fires.
I don't have the skill to do it myself, but I'd love to see an analysis of whether it would make more sense at this point to do solar/wind + batteries and backup generators for at least the smallest and most remote communities.
By ZeroGravitas 2025-05-2116:39 Australia has just completed 5 years of feasibility studies on this:
https://www.dcceew.gov.au/energy/programs/regional-remote-co...
and moved to the pilot phase:
https://arena.gov.au/funding/rmp/
A review of some of the feasability studies carried out in phase one:
https://www.sciencedirect.com/science/article/pii/S221462962...
By pjc50 2025-05-227:28 The Scottish island of Eigg has its own micro grid built by the residents which works like this.
Would imagine it's the initial cost of seeing all that up, and then the cost of maintenance. For me personally, where do you even start?
It grew organically so there was never a huge cost Really, except when we decided to build a building for The power plant because it was getting out of hand. It’s been a few thousand dollars a year in growth as we add batteries and panels. Also a bit of labor for installation of course, but we handle that in house.
> It grew organically so there was never a huge cost Really,
Ahh, the accounting style of hobby projects. I’m very familiar with this because I do it, too.
Nothing ever feels expensive if you just never add it all up and value your time at $0 because it’s fun.
The total cost of the system so far is about $87k, and operating cost is around 4000 a year (includes equipment amortisation, slow expansion, direct operating costs). In all, for several homes, and a farm it’s very affordable. Getting power hooked up to a single house from the utilities is about $9000, so our buildout is roughly 2x what we might have spent just to get hooked up to the grid.
We do buy carefully, and all the engineering is done by me. We have employees on the farm so much of the labor of installing underground cable etc was “free” (lol).
Still, we are miles ahead of our costs if we were hooked up to the grid (which also would have cost us an additional $20k just for poles to get close, and we still would have had to bury the cables on campus along with the water and data, if we didn’t want ugly poles all over, so that part is a wash)
I spend about 4 hours a week on utilities based projects, mostly engineering monitoring and control systems so that I spend less time working on the utilities. (So, futzing around with electronics because I have an excuse to) it feels like meaningful work that I care about, so that’s nice.
By bityard 2025-05-2118:18 That sounds incredible. This is the first year I've really started digging deep into solar generation and battery storage and it's one big fascinating rabbit hole.
I've looked at it from a bunch of different angles and keep coming to the conclusion that for rural and suburban areas with the space for panels, off-grid solar is the future.
By BubbleRings 2025-05-2115:122 reply Thank you so much for these posts! It makes me very optimistic about the future.
For the longest time we all watched from the sidelines, hoping that the desire to turn off coal-fired power plants, and research often funded by tax dollars, would get the ball moving on solar. Now that the market has its magic invisible hand on that ball, it seems clear to me we have a path out of this mess.
Rant your stupid “drill baby drill” crap all you want magats, we are going to solar, wind, and fusion our way to a better world, and there is nothing you can do to stop us.
By strawhatguy 2025-05-2116:451 reply That’s silly, why make it political? If anything the political encroachment came from the green crowd first, cafe standards, EV mandates and the like.
The best way forward has always been to explore all energy avenues, and that will include fossil fuels as well. At least you’ve included nuclear, but left out fission, strangely, which is the best hope of electric generation replacement we currently have.
I’m tired of this team blue for electric (except Tesla now, lol) and team red for oil. They are choices with trade offs, and are friends, not enemies.
By bloomingeek 2025-05-2118:312 reply No offence, but everything is political. Much of our lives are controlled by laws. These laws are all politically controlled. To say it's silly to make something political, usually suggests your supported political slant is difficult to justify. Trade offs are only possible when the party in charge is willing to work with EVERYONE, we don't have that now. Thus the criticism.
By strawhatguy 2025-05-2316:50 Politics works through division by way of laws. Reduce the laws, reduce the division, and therefore politics.
By mensetmanusman 2025-05-2212:43 Politics is simply preference.
Fission first! Let's build more nuclear power plants too. We know how to do it, and it's only so expensive because we got scared and stopped. Economies of scale for clean, safe, reliable baseload power.
Turns out, I'm already on fission.
What I've done is tap into an existing fission reactor. It's some distance from my house, but there's a lot of excess energy there leaking out. I put up some collectors to capture it.
Was really quite cheap to do, and I don't have to pay anyone to actually run the reactor.
> and value your time at $0 because it’s fun.
I don't know if you were being ironic or not but... that's an absolute truth. Our free time doesn't have a fixed rate. It doesn't have a rate at all. What you do during free time can be basically seen as either:
* a chore you don't like to do
* something you like to do.
Any task can swing between those states depending on your mood. If installing your own solar plant or self-host your server rack (as OP is doing) is something you enjoy doing, then yes, it costs exactly $0 in labor.
By thedanbob 2025-05-2116:04 Agreed. I get asked to repair electronics for people quite often and I charge drastically differently for labor depending on whether I will enjoy the job or not.
How much are you valuing your own time? Theres money cost, then theres time cost and the final one is in more remote communities with cold weather… insurance costs on failure…
Also to be clear - good on you for building out rural off grid electrical. Its a fun project and satisfying no doubt (outaide of costa)
By Moto7451 2025-05-2113:53 I don’t know the OP’s situation but I’ve seen that many coffee growers have to do this because in high altitude tropical areas there is simply no one who will do the work anyway. They also have a very different regulatory structure in practice to what we have in the continental US and Europe.
I’ve spoken to people from Rural Georgia (which is about an hour from Atlanta depending on the direction you’re driving) in Microcenter that are usually there to wire up their farm or factory with sufficient network capacity to keep production rolling. They have mentioned that they have had to do their own trenching for last mile for various services. Sometimes that means they literally drive down to Herc rentals, pick up a trenching machine, and do it themselves since the wait for someone else to do it is months away and that’s a long time if your business needs internet, water, power, etc.
By K0balt 2025-05-2210:39 It’s been an adventure, but it would be disingenuous to imply that a don’t enjoy the challenge. It is very satisfying to have your work be so useful to many people. As for failure, we have them sometimes, but our casualty downtime for the last 6 years is <15 minutes. We have a highly redundant system that can run on as few as 2 of the 6 inverters, 8 separate battery banks, 16 separate panel banks with 9 separate charge controllers, 2 generators, and a completely separate redundant inverter for emergency power, as well as a separate power reserve system for control and monitoring power.
By teleforce 2025-05-2412:12 This is truly interesting and inspiring.
Is there any documentation of your solar microgrid systems for learning purposes? Or better can anyone visit your farm for learning the microgrid systems?
I just found these article back in 2017 and 2022 on microgrid installation in the Caribbean and they looks like promising off-grid solutions for tropical islands [1],[2].
[1] Why Solar Microgrids May Fall Short in Replacing the Caribbean’s Devastated Power Systems (2017):
https://spectrum.ieee.org/should-a-devastated-caribbean-leap...
[2] As rich nations haggle over climate solutions, storm-ravaged Caribbean is taking matters into its own hands (2022):
https://edition.cnn.com/2022/11/15/world/caribbean-solar-pow...
By antisthenes 2025-05-224:57 > It’s strange to me that people in rural areas pay for electricity. It makes no economic sense, at least here in the Caribbean.
When I took a vacation to Aruba, I was very disappointed to see very limited solar and EV adoption. Public transportation (buses) were running on gas, as were most personal vehicles.
It was nuts to me considering there was only 1 overcast day out of the 7 I was there, and you definitely don't need any energy for heating, ever.
By jhfdbkofdchk 2025-05-2116:181 reply reminds me of that Hunter S. Thompson quote from Fear and Loathing in Las Vegas, "Not that we needed all that for the trip, but once you get locked into a serious [solar power setup], the tendency is to push it as far as you can.”"
By K0balt 2025-05-222:36 Lol. Definitely!
It’s a ratchet:
Need more power: Buy more panels, they are cheap! Need more power: Buy more panels, they are cheap! Need more power: Buy more panels, they are cheap! Need more power: Can’t buy more panels, need more batteries to stabilize the system. Thankfully , batteries are getting better and cheaper! Lots of power, so much we need to find new ways to benefit from it! Need more power: Buy more panels, they are cheap! ……
The economics of panels are basically 20 percent APR here over 20 years. Over 40 years it drops to around 10 percent for out of service life panels.
What's your farm? How can someone reach out to buy small amounts of coffee from you, say 2-3 70kg bags?
Would love a write up or links to resources for water extraction and treatment if you’d oblige.
I don’t have much in the way of links, but I can give you an overview.
We have a fair bit of vertical scale in the terrain here. We extract our water from a shallow well in a natural crevasse between ridges. It is made of concrete blocks stacked in a circle, filled with gravel and pinned with heavy rebar. The above ground part is finished in a regular fashion, with the blocks filled with concrete and a concrete cap. The well is built of a circle of 12 blocks, and is about 16 feet deep- where we encountered hard bedrock. An underground stream flows over this bedrock, which we extract from.
This raw water is pumped to a 300 gallon manifold tank about 160 feet above the extraction point using a 1HP centrifugal pump. From there, it flows down to the processing facility, where it is sediment and carbon filtered before flowing into either the 2600 gallon cistern, or back up the hill a bit to a 450 gallon upper campus distribution tank. Water passing through the processing facility is filtered and chlorinated, with the exception of the upper campus water, which is only filtered.
The upper campus water flows to cabins in the upper campus, and also serves as the input water for the RO system. The RO source water is pressurised by another centrifugal pump to 70psi, and is fed through a pair of 150GPD membranes after being filtered to 1 micron and passed through another carbon block. We run a 4:1 “waste” ratio to give us good life on the membranes (typically a year). The mineral rich “brine” flows into the 2600 gallon cistern and is used in the regular water.
We warehouse the drinking water in a 500-gallon tank at the processing facility.
There is a dual distribution system for water on campus. From the cistern at the processing facility RO water and regular water flows through underground tubing to a network of 5 utility huts where it is distributed to various homes and outbuildings. Each building then passes the main water through another carbon block to catch chemicals and chlorine, and drinking water gets mineralization and carbon again at the point of use.
The underground distribution network also carries 3 phase power, HVDC for solar, separate fiber optic networks for security, control, intranet, and ISP, as well as cat6 cables for RS485 control subsystems. The tank levels, pump controls, power distribution and usage monitoring, emergency and automatic casualty control shutoffs, etc are all operated over rs485 and modbusTCP to a server. It’s a lot of off the shelf stuff and some custom stuff that i have built. Someday I need to do a write up on that lol.
Anyway, that’s the view from space.
By el_benhameen 2025-05-2115:581 reply This is cool as hell. Sounds like you keep pretty busy, but if you ever had the inclination to write more about it or post some pictures somewhere, I for one would love to see.
By K0balt 2025-05-2213:19 Thank you for the encouragement. It’s on my bucket list.
By K0balt 2025-05-2213:43 There is a few more details, especially of the early days, on my extremely neglected and out of date blog https://vivavistadelmar.wordpress.com/blog/
Also, yeah, I know. Wordpress wasn’t a great choice even years ago when I set up the blog, but I was going to self host as a static site “soon” anyway and I needed to get started… almost good enough is the mortal enemy of adequate.
By networkisfine 2025-05-2117:151 reply Very interesting. I'm looking to do something very similar on a farm.
Would you mind sharing some more design details?
Questions that come to mind: What products are you using? Are you doing any AC-coupling between inverters? If not, are you just running your PV wires between buildings? Are you stepping up your AC voltages to 480v or so to cover greater distances with less loss? Thanks!
By K0balt 2025-05-2214:57 Running the inverters in parallel synchronized in a three phase configuration, 2 per phase, 224/130. Since the power plant is centrally located, our longest run is about 270m. It’s at the edge of what we can do with the cable we have buried, so if we need to extend or add significantly more capacity we will probably go up to 440v for that segment, with a substation at the PED4 utility hut. Better efficiency in step up/step down is one of the reasons we chose 3 phase power.
The panels are mostly centralized with each string being a home-run to the power plant but we are building out an additional 10KW on a rooftop about 200 yards away, so that will be 600VDC buried cable.
We are testing small ( panel-back attached )grid-tie inverters for supplemental power at point of use, but we will see how much we can add before it results in stability issues. It would be great to be able to put a panel or two wherever it’s handy and just tie each panel separately into the ac distribution.
By pryelluw 2025-05-2113:52 Where in the Caribbean?
Naive question, why run inverters?
Wouldn't it be more efficient to run direct DC appliances?
We have a building on our farm without power and it'd be ideal to be able to charge batteries and run lights at night
It seems to me that we would have to upsize batteries in order to make up for the loss in converting to AC
> Dumb question, why run inverters?
Can't say for OP, but DC appliances are just difficult to find, usually more expensive due to economies of scale and not as uniform in voltage (12/24/48V) as AC appliances. If your battery is in a shed somewhere it's also much easier to run a smaller gauge AC wire than setup distribution for your DC power.
Most large system are also 48V so you need to get it down to 12/24V which adds components anyway, at which point you might as well just have an inverter and not worry about any of that.
By bruce511 2025-05-2120:01 You also need some sort of battery management, and inverters typically have this built in as well.
So yeah, you can get by without an inverter, but then you need a battery charger manager so as not to overcharge, and (depending on the battery chemistry) something to cut off the battery as it runs down. (Lead acid for example shouldn't go below 50%).
By K0balt 2025-05-2214:39 As a parallel answer, for small systems this can make sense, although in anything larger than a single small cabin or small boat it probably is borderline these days. Modern inverters are quite efficient, and DC distribution carries a lot of issues, and gets downright dangerous at higher voltages necessary for large appliances.
20 years or so ago I rebuilt a 60’ schooner, and even on that scale AC was by far the best choice. Just the wiring for a DC system was more expensive then double Refund inverters, and most of the appliances were actually less efficient, since they had their own inverters inside them (DC-DC converters). In all there just wasn’t any justification, and corrosion is another issue on boats, so we went all AC.
By K0balt 2025-05-222:41 To be clear, we are distributing power over about 600m of length, so it has to be high voltage. HVDC is very very dangerous, I would not want it in my house. Not only that, it’s hard to find things that are efficient and work on high voltage DC. Since our batteries are already 60V, our inverters already are very efficient, it’s simply not worth it. Panels are so cheap, it almost doesn’t matter how you are trying to save power, the answer is that it’s almost always cheaper just to buy more panels.
Not who you're asking.
I really don't see why we're still using A/C inside our houses / apartments. I understand that the transmission loss is lower when sending A/C, so it makes sense, but then nearly every device in my house has their own AC to DC converter. Just have one AC-DC converter per building.
I'd like the future to just be USB-C sockets in my house. We have USB-C PD 3.1 which supports up to 48v, I imagine that would be good for all devices.
There are probably safety reasons why this future might be difficult.
By bityard 2025-05-2118:14 That would have been a good argument to make a decade or two ago but these days switch-mode power supplies are very efficient, and GaN ones even more so.
I have a small mess of 12-ish volt computer/network equipment in the corner of my office and looked into running it all off of one $40 high-amp power supply to eliminate all the wall warts and bricks. By the time I figured out power distribution and termination, buck/boost converters for the things that aren't 12V, it all seemed like a lot of work compared to just spending a couple hours tidying up the cabling and hiding the wall warts.
You can live in the future now and install power outlets with USB-PD built right in, although a quick glance suggests they top out at 65W. Fine for phones and tablets, might not keep a gaming laptop charged while in use.
By K0balt 2025-05-2213:25 A lot of appliances need >1kw.
This requires higher voltage and robust connectors.
That level of DC is quite dangerous compared to AC for many reasons.
Also, unless you want to have 60lb extension cords the size of bratwurst, you need to go high voltage. High voltage DC is its own kind of devil, and is something I would not want in my household except in very isolated, self contained places.
High voltage, high current DC is on yet another level of mortal threat, able to do cool tricks like making extensions cords burn from one end to the other like cartoon dynamite fuses. Also, absolutely the best for accidental electrocution, severe burns and flash blindness, and setting otherwise fire resistant structures thoroughly aflame.
By eternityforest 2025-05-235:18 At USB voltages, one or two volts of drop is significant. You need very heavy cables, and for every voltage USB-PD allows you'd need another set of cables.
Also, some devices run directly on AC, or need more than USB can do, even with EPR. Since we already need AC for that, why add more wires when USB chargers are cheap and efficient and reliable these days?
By wolrah 2025-05-2217:42 I'm not an electrical specialist but there are three major reasons I'm aware of that AC "won" at normal household/commercial power levels:
1. Switching. If you go look at your favorite part supplier you can find a bunch of switches that are rated to switch 250 volts AC and pass 16 amps, enough for basically any standard household outlet anywhere in the world. Those same switches are only rated for 24 volts DC. Why? Because of arcing. AC voltage passes through zero twice a cycle, which means that any arc that may be formed will self-extinguish within a hundredth of a second. DC doesn't do that, so the arc potential has to be limited either by reducing the voltage or increasing the size/complexity/cost of the switch/relay/contactor itself. This also applies to any connectors that may be unplugged under power like wall outlets. If you want to do the same amount of work with DC as you do with AC you basically get the choice between doing it at lower voltage with thick expensive wires or doing it at higher voltage with expensive switches, relays, outlets, etc.
2. Motors. Synchronous AC motors are EVERYWHERE. They're simple, cheap, efficient, and as long as they're not overloaded they run at a consistent speed determined by the number of magnetic poles in the motor and the AC frequency. If you have an appliance or power tool that runs on mains power and does not offer motor speed control (or only offers two or three speed settings) it's likely one of these. Native DC motors are also cheap and simple but but have very different performance characteristics, no native mechanism for precise speed control, and flow current through the rotor which requires brushed contacts that wear out over time. "Brushless DC" motors are actually AC motors paired with a controller which is more or less a DC->AC inverter, adding cost and complexity that may not be otherwise necessary or beneficial to the application.
3. Voltage conversion. AC can use simple wound transformers to efficiently trade voltage for current or vice versa using nothing but wire and metal. You might have used or even built one in a middle-school era science class. DC voltage conversion on the other hand, the simple methods are inefficient and the efficient methods require high-frequency electronics which only became inexpensive enough to go mainstream in the last 50ish years.
None of these are insurmountable problems of course, especially these days when switch-mode power supplies, inverters, VFDs, etc. are cheaper than ever but they still make things more complicated and require going against in some cases multiple lifetimes of industry inertia to purchase equipment produced in much lower volumes which means higher costs, and especially for home applications where size and weight are not the biggest deals it can often be easier/cheaper to just run a larger solar/battery setup to counteract the efficiency losses.
In the RV and boat worlds where size and weight matter you'll find a lot more DC appliances, but those are also generally smaller capacity than a household equivalent.
By h4ck_th3_pl4n3t 2025-05-2121:28 This sounds awesome!
Do you have a tech blog or writeup on what things you used, what parts broke down, or what kind of things needed to be fixed over time?
That sounds like a dream gig. Do you find it satisfying running your own utility?
By K0balt 2025-05-2213:20 It is enormously satisfying to be doing something that is so useful to people close to you. I just wish I could focus more on that instead of other projects, but c’est la vie.
I have a solar system in my house in london. 5kw, 13kwhr battery. I am self sufficient from end of march to october.
I recently got a second hand electric car. I bought an EV plug (total fucking ripoff. its a fucking plug with a contactor, RCD and a CAN interface. no way is that worth fucking £600)
It has some basic control to allow me to charge from excess solar. What is not easy to do is charge at night without draining the house battery. Its fine for me, because I have Home Assistant, with enough fiddling I can get all the systems to talk to each other to play ball. (to add to the complication, I'm on a variable rate tariff, so price can be negative or £1 a kwhr)
I would really love a "house power API" that would allow a "controller" to locally control the power behavior of all the things in a house. Because at the moment, a "normal" person wouldn't be able to charge their car and have house batteries and have solar, and optimise for cost.
If your electrical installation allows it: You can connect your ev plug before the battery so that it does not drain the battery. You can do this by placing the fuse/connection before the measurement clamps for the battery. Somewhere in between your mains connection and your battery/solar system.
This way the battery does not see the load and does not provide power to your EV.
That way you can still use excess solar (before you inject it into the mains) to charge your car + you do not pull power from your battery :)
By KaiserPro 2025-05-2110:24 The ideal solution is for the battery to have a third set of clamps to measure the EV. But as I don't have installer access to the software (centrally managed for the win) I'm not sure thats possible.
I might ask to see if thats possible. I probably need more panels to cover the winter load.
Would be interesting to know how London compare to Sweden. Electricity here are generally about twice to four times more expensive during the winter than during the summer, and energy consumption is about twice the amount during winter compared to summer. On average people here spend around 75% of the total energy bill during winter.
By KaiserPro 2025-05-227:15 Generally people are on fixed rates that are updated yearly. Its pretty "new" to get variable rates here.
https://agilebuddy.uk/historic/agile
has some historic prices. We still use gas for heating, so there isn't so much seasonality for consumption. (there is, but not in the same way).
What does affect price is wind. you can see in december there were both record high prices and record low. The more wind we have the cheap power becomes. so in winter its generally quite cheap, but then also it can flip and become very expensive, because gas imports are expensive.
By throw0101b 2025-05-2110:53 > no way is that worth fucking £600)
Liability coverage, and UL certification (or UK/EU equivalent), for the company is. Though see perhaps:
* https://en.wikipedia.org/wiki/OpenEVSE
> I would really love a "house power API" that would allow a "controller" to locally control the power behavior of all the things in a house.
With regards to EV and the grid, see perhaps:
* https://en.wikipedia.org/wiki/ISO_15118
* Also: https://www.ampcontrol.io/post/what-are-ocpp-iec-63110-iso-1...
For an (industrial) electrical communication protocol, perhaps:
Midnight Solar are the OG company in off grid and they have a "waste not" feature from way back that triggers any device when the parameters you set are reached, ie: float voltage, and/or other things, like a second set point where power would be sent to a third load, like the grid or water heating. https://www.midnitesolar.com/ hard core techies, even had the pleasure of detailing my inadvertant and unsucessfull attempts to melt one of there controlers.......literaly had a main lug get loose, and the panels arc melted the lug to slag, and it lived. in any case, there web site has a wealth of info on what is possible, and to look for elsewhere
By _whiteCaps_ 2025-05-2114:351 reply Midnite Classics are great... But the web APIs seem to be deprecated. Do you know of any tools that can get data off them?
By metalman 2025-05-2123:24 nothing other than what is published in the manuals, there is a link to a third party software for monitoring the clasics, but if you want the inside story, call them....they answer the phone and speak many dialects of techinese there latest offering is a game changer "the 1" it does everything 11kw of 600 volt solar in, to any kind of 48 volt battery, and grid tie, and single,split phase and 3 phase 208 volt ac out, one box 98 lbs, 5k list you can install 200 % extra solar for low light, or norther locations specs are wild https://www.midnitesolar.com/productPhoto.php?product_ID=766...
We have https://www.myenergi.com/ for our car charger and it seems to be able to integrate batteries, charging and panels like you suggest, only you have to go all in. We have parts of it and are tempted to use more, but the lock-in angle is a bit off-putting
By KaiserPro 2025-05-2113:39 Yeah I have a Zappi, but as you know its got no local API, and it doesn't like getting warm. However it _cant_ control my battery directly, because its made by tesla. (I mean thats also my fault....)
I have also heard that if you go all in it works much better. It does have the nice feature of diverting to other devices instead of the grid, and giving priority to certain devices.
By SoftTalker 2025-05-2116:06 If your rates can go negative you should be charging the car and house batteries at that time if possible and then selling back to the grid at peak times. Does your home assistant get real-time rate data and can it facilitate that?
I mean, it's a bit more than a contactor and an RCD, it also has PEN fault detection because TN-C-S is how most of us are wired up to the grid.
Then for use with smart tariffs like IOG there's a microcontroller, cloud gateway for them to hook into for OCCP to turn on and off the charger when the grid is cheapest/greenest etc.
So £600 is about right, once you add in R&D, certification, profit margin, warranty claim % etc.
> Then for use with smart tariffs
I wish it had all of that. I would actually pay for that. The Zappi from myenergi promises much but fails to deliver.
By philjohn 2025-05-2118:15 That's odd - I've got the Zappi and it works perfectly with Intelligent Octopus Go. Plug the car in, have a HomeAssistant automation that detects this and sets the "charge to add" on Octopus and enjoy the car being charged the next morning.
I always recommend hardwiring it though, rather than relying on Wifi through a brick wall.
By hkgjjgjfjfjfjf 2025-05-2116:47 [dead]
I did build my own solar system too. In Switzerland.
Took me 1-2 month planning and then 3 month building it alone nearly each day. Sept 2023 til Xmas 2023. Got all the hardware from a PV dealer friend on his purchase price level. Even 24 panels I have put myself alone onto the roof. With two persons it was a bit better.
I've got: 420w x 71 Trina solar panels and two SolarEdge inverters. SE10K Hybrid and a SE17k. Also a 24kWh BYD LFP battery.
All prices without state funding: Offers from local installers for 56*410W Panels without battery were around 65k CHF.
I've paid now 44k CHF including every kind of cost associated with building it.
Should write a blog post about it :-)
Next project is a solar fence with 6kWp.
What do you do with that much electricity? Was it necessary to over-dimension for winter?
Of course it is a bit oversized.
We’re living in a big river valley where we have fog from October until March. On some days in November the fog is so dense that the whole system does not produce any kind of energy. On the other days the produced kWh are enough to charge the battery.
We have a heat pump (extrem efficient), servers, one electric car, etc which consumes all together around 13MWh per year. The solar system produces around 27.5MWh. Most of the energy gets fed back into the grid.
We’re currently investigating to connect the neighbour houses physically to us. But that takes even more time here :-(
FYI: Neighborhood-level connections are changing starting next January (look up RCP and CEL).
By butshouldyou 2025-05-2118:391 reply They're in Switzerland.
By amenghra 2025-05-2120:42 Yes, how neighborhood-level connections are setup in Switzerland is changing next year.
See eg https://www.swissolar.ch/fr/connaissances/nouvelle-loi-sur-l... (post written in French)
By raphael_l 2025-05-219:16 I would also be interested in the reasoning here!
Just for comparisons sake, our 8.6kwP setup with a 10kwH battery cost us (after subsidies from governemnt) appr. ~€11.5k. Haven't received all the subsidies yet, so the total will be lower by about 1.5k (I think). Everything was done through installers, we didn't lift a finger (also couldn't, because when it comes to electricity I have as much experience as the dog next door).
If I had more due diligence before I would have scaled up the panels up to at least 10kwP, for future proofing probably to 12kwP. This is mostly just to make sure winter is covered better, as our production is really low as we have a 10° flat roof installation.
If you have an EV that can be charged only at night, a big battery is required.
By cyri 2025-05-219:45 For solar excess charging I use evcc.io
When I charge the car via battery then only down to ~75% for now. The remaining energy is needed by the house during winter months.
By kragen 2025-05-2112:11 How much did you pay for the panels, and what's your capacity factor? (Kilowatt hours produced on average per nominal peak kilowatt.)
