Building my own solar power system • Hacker News Board

Re: Building my own solar power system

#241

Post by coryrc » Wed, May 21, 2025, 4:48 PM UTC

baby_souffle wrote: post #177

Loughla wrote: post #166

Earlier quoted context omitted.

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.

> 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…

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.

Re: Building my own solar power system

#242

Post by looofooo0 » Wed, May 21, 2025, 5:10 PM UTC

sneak wrote: post #105

looofooo0 wrote: post #35

Earlier quoted context omitted.

Not so easy to reduce the grid load all the time, needs a big battery for every night and for multiple dark days you still need the grid a lot.

Paying reasonable rates for generation also incentivizes distributed storage for anyone who wants to buy batteries and help load shift. Large neighborhood batteries seem to make a lot more sense to me than batteries in every home.

Would be nice, the rate could be grid size battery/PV + cost savings from localized production. Not sure if it is economically feasible then.

Re: Building my own solar power system

#243

Post by networkisfine » Wed, May 21, 2025, 5:15 PM UTC

K0balt wrote: post #144

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 an…

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!

Re: Building my own solar power system

#244

Post by alex-moon » Wed, May 21, 2025, 5:20 PM UTC

lazide wrote: post #149

kragen wrote: post #137

Earlier quoted context omitted.

If the objective is to reduce the number of hours you're not self-sufficient for a given battery size, or reduce the size of your expensive batteries, even a couple hundred watts could make sense. https://www.amazon.com/NINILADY-Vertical-Generator-Controlle... is a 600-watt-peak wind generator, designed for 11m/s winds, for sale in the US for US$300, presumably much cheaper in countries that aren't descending into kl…

The issue is the payback is not worth the hate from your neighbors and capital cost. at least solar panels are quiet.

Hence "community energy" - you do it with your neighbours - this model has worked in Scotland before - https://www.resilience.org/stories/2019-07-16/rebel-cities-t... - here is one from earlier this year - https://www.thenational.scot/news/24993445.local-groups-bid-... - and recent changes in planning legislation mean we should be seeing more of these in England in the near future - https://communityenergyengland.org/pages/community-wind

Re: Building my own solar power system

#245

Post by arwineap » Wed, May 21, 2025, 5:28 PM UTC

K0balt wrote: post #144

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 an…

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

Re: Building my own solar power system

#246

Post by danans » Wed, May 21, 2025, 5:29 PM UTC

> Missing site diagram placard at MSP

I got dinged for this on the first inspection of my own self-installed solar+battery system.

A lot of signage companies don't know how to do the placard, but the company that I found that knows how was PVLabels:

https://www.pvlabels.com/04-645-map-placard/

Re: Building my own solar power system

#247

Post by somanyphotons » Wed, May 21, 2025, 5:32 PM UTC

Havoc wrote: post #231

Suspect it would have been cheaper to invest money in upgrading the homelab and aircon to more efficient. Not downgrade, but rather moving to newer lith nodes etc. Tackling the usage before bigger battery system often makes sense

The solar system will pay for itself within N years, and then he has free power for as long as the batteries and panels last

Re: Building my own solar power system

#248

Post by belval » Wed, May 21, 2025, 5:32 PM UTC

arwineap wrote: post #245

K0balt wrote: post #144

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 an…

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.

Re: Building my own solar power system

#249

Post by danans » Wed, May 21, 2025, 5:35 PM UTC

gdubs wrote: post #230

This disabused me of the notion of doing it myself, lol. This is super impressive. Hope to one day be confident enough in electrical work. That and plumbing are the areas of home improvement that I still just would rather sub out. But, this is such a cool article. The quotes on solar installs for some reason seem a lot higher than what you'd expect, given all the charts showing the absolute cratering of solar energy…

> This disabused me of the notion of doing it myself, lol.

The author did a very custom setup. If you want to DIY with a pre-integrated setup, you can enroll in Enphase's self installer program, and complete their online coursework:

https://enlighten.enphaseenergy.com/manager/registration?_gl...

I think EcoFlow may have a similar option.

Re: Building my own solar power system

#250

Post by vasusen » Wed, May 21, 2025, 5:37 PM UTC

thegrim33 wrote: post #218

It's kind of telling/ironic that the author gripes (whether rightfully or wrongly) about PG&E wanting more return on investment due to their risk of doing business in California, but when the author decides to build their own power system to not deal with PG&E, literally almost every paragraph related to their planning/setup contains a mention of some different California/city regulation that the author had to meet o…

This is the key issue. We are over-regulated.

We rebuilt our house in the SF Bay Area in 2022 and went fully electric, no gas line anymore. It was really sad that I couldn't resuse any of my previous 12 kwh solar panels that were fully functioning and had another 10-15 years on them as they wouldn't match the new regulations.

I tried to get them installed on a separate area in my own backyard for off-the-grid charger just for my car, but you are not allowed to have a big off-the-grid system unconnected to PG&E. No electrician was willing to help with risk of losing license. The author was lucky that his dad could help with electrical.

Due to similar issues, I couldn't find anyone to take them for free as well. Demo dad was a truly sad day to watch these perfectly functioning solar panels being destroyed by a crane.