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Building my own solar power system

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Re: Building my own solar power system

#161

Post by KaiserPro »

bencyoung wrote: post #139
KaiserPro wrote: post #90

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 dra…

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

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.

Re: Building my own solar power system

#162

Post by K0balt »

Aurornis wrote: post #154
K0balt wrote: post #148

Earlier quoted context omitted.

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.

Re: Building my own solar power system

#163

Post by KaiserPro »

philjohn wrote: post #133
KaiserPro wrote: post #90

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 dra…

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 %…

> 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.

Re: Building my own solar power system

#164

Post by nullpoint420 »

Aurornis wrote: post #150
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…

> 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…

I’m jealous. Where I live in California the off peak rate is $0.32/kWh and peak rates are $0.58/kWh.

Re: Building my own solar power system

#165

Post by Moto7451 »

Aurornis wrote: post #150
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…

> 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…

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...

Re: Building my own solar power system

#166

Post by Loughla »

nullpoint420 wrote: post #164
Aurornis wrote: post #150

Earlier quoted context omitted.

> 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…

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.

Re: Building my own solar power system

#167

Post by pryelluw »

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…

Where in the Caribbean?

Re: Building my own solar power system

#168

Post by Moto7451 »

boringg wrote: post #153
K0balt wrote: post #148

Earlier quoted context omitted.

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.

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)

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.

Re: Building my own solar power system

#169

Post by mdaniel »

throw0101b wrote: post #125
jmb99 wrote: post #15

Earlier quoted context omitted.

My hard drives alone pull 200W idle and I don’t have that many. Cooling fans (in servers) pull 150W total most of the time but can be up to 300W. Each 10GbE NIC pulls ~40W. PoE switch gives ~30W to each of my APs, and uses ~80W itself, so there’s another 300W. All of my RAM pulls about 250W (admittedly there’s nearly 2TB of it in the rack, but still). Start adding up CPUs idle/average/max power and the numbers get wa…

> Cooling fans (in servers) pull 150W total most of the time but can be up to 300W. Oxide Computer found that going from tiny 20mm fans to 80mm dropped their chassis power usage bigly: they found a rack full of 1U servers had 25% of its power going to the fans (efficiency is to the cube of the radius). * https://www.youtube.com/watch?v=hTJYY_Y1H9Q

My mental model is that such a choice is why a data center is deafening: all those tiny fans spinning at hella rpm

Re: Building my own solar power system

#170

Post by thebiss »

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…

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.

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