Electrikery...

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TheGreenGoblin
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Electrikery...

#1 Post by TheGreenGoblin » Sat Dec 11, 2021 4:04 pm

Though you remain
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"To be alive
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Your destination remains
Elusive."

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Re: Electrikery...

#2 Post by k3k3 » Sat Dec 11, 2021 5:44 pm

I thought it was rude to Poynt...

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Re: The really boring and totally pointless snippets thread V

#3 Post by VP959 » Fri Sep 23, 2022 6:43 pm

We have enough battery storage to keep the house going for around 2 days as long as we're careful, and switch to using a camping stove for cooking and making tea. We already run on battery power most of the time, anyway, as peak rate electricity is so expensive. In summer the batteries mostly get charged from the solar panels, but if there's not enough sun we just switch to charging them from cheap electricity overnight. If bad weather's forecast all I need to do is make sure the batteries are topped up before it's due to arrive.

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Re: The really boring and totally pointless snippets thread V

#4 Post by Fox3WheresMyBanana » Fri Sep 23, 2022 7:01 pm

Sound move.
I will be installing battery storage and solar panels next year. My inverter/charger can also use the mains to recharge.
I will be mounting my panels on a 2-axis tracker (homemade) to maximise winter insolation.

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Re: The really boring and totally pointless snippets thread V

#5 Post by VP959 » Fri Sep 23, 2022 7:06 pm

Fox3WheresMyBanana wrote:
Fri Sep 23, 2022 7:01 pm
Sound move.
I will be installing battery storage and solar panels next year. My inverter/charger can also use the mains to recharge.
I will be mounting my panels on a 2-axis tracker (homemade) to maximise winter insolation.
Make an absolutely massive difference for us. I installed about 6kW of solar panels back in 2014, when building the house and added about 21kWh of battery storage a couple of years ago. We now use very little peak rate (daytime) electricity. Over the past 12 months about 98% of our electricity from the grid has been at the cheaper overnight rate. From about the end of March through to about the beginning of October we can pretty much run off the solar panels, with excess sorted in the battery or the car. At most we may use about £1 per day of grid energy. In winter that goes up to about £3/day from the grid, but I can live with that.

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Re: The really boring and totally pointless snippets thread V

#6 Post by llondel » Fri Sep 23, 2022 7:11 pm

We seem to have managed this past year at parity, I think we pulled about 20kWh more than we stuffed back into the grid, which I never expected. Now I am preparing to do battle with PG&E over how much they think we owe them for the near. California has Net Energy Metering, which means we should only get charged for the difference, so I may have to ask them how they arrived at $200 for 20kWh difference.

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Re: The really boring and totally pointless snippets thread V

#7 Post by Fox3WheresMyBanana » Fri Sep 23, 2022 7:32 pm

Methinks we should drag this off to another thread - is there one?
I have more questions for you both.

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Re: Electrikery...

#8 Post by TheGreenAnger » Fri Sep 23, 2022 8:16 pm

Admin2 does read all the threads here! ^:)^

My disreputable cousin, the GreenGoblin!
My necessaries are embark'd: farewell. Adieu! I have too grieved a heart to take a tedious leave.

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Re: Electrikery...

#9 Post by Fox3WheresMyBanana » Fri Sep 23, 2022 8:26 pm

VP959 - Interested in how you sized your system, and panel orientation.
Llondel - my system will be off-grid as we have naff grid-tied arrangements here, but that may change. I am interested in the nitty-gritty of how grid-tied is working out, esp. in dealing with both government and the power company. A neighbouring province recently had the power company try to rewrite the grid-tied agreement (basically halving the rates), and the government only stopped them after a huge outcry.

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Re: Electrikery...

#10 Post by VP959 » Fri Sep 23, 2022 8:40 pm

Fox3WheresMyBanana wrote:
Fri Sep 23, 2022 8:26 pm
VP959 - Interested in how you sized your system, and panel orientation.
Llondel - my system will be off-grid as we have naff grid-tied arrangements here, but that may change. I am interested in the nitty-gritty of how grid-tied is working out, esp. in dealing with both government and the power company. A neighbouring province recently had the power company try to rewrite the grid-tied agreement (basically halving the rates), and the government only stopped them after a huge outcry.
The sizing of the panels was simply the maximum number we could fit on the South side of the roof. We could get 25 panels up there, with a thin band of slates around the edge (the panels are set into the roof, so are the watertight roof covering on that side). That gave us 6.25kWp, which turns out to be around 30% more over the course of a year than we use. The bugger is that we generate most power when we don't really need it, so we stuff as much as we can into the cars, run the aircon in summer just to use the power, and then end up buying power from the grid(albeit overnight when it's cheap) in the winter.

There was no science involved, as the cost of the panels wasn't that much different from the cost of the slates we'd have had to buy (it was a new build). I'm in the process of adding another 2.4kWp of panels to form a car port, again because solar panels weren't much more expensive than roofing panels, so it was a bit of a no-brainer to fit them.

We don't get paid a lot for exporting energy to the grid, about 1/6 of the cost of buying electricity, so hardly worth the effort. Definitely worth storing the excess in batteries or the cars, though. We both run EVs now, and haven't paid to charge either of them since the end of March. Saves a bit of cash, but also gives the government the finger, as about 70% of the cost of fuel here is tax and duty, and at the moment the government haven't found a way to tax people running their cars for free from their own solar systems.

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Re: Electrikery...

#11 Post by Fox3WheresMyBanana » Fri Sep 23, 2022 8:49 pm

Thanks.
What is your typical energy usage in kWh/day?
Do you happen to know your sunshine hours/year?
Is your roof exactly south?Slope?
I have a hot tub that will make use of the summer energy excess!
I also use a/c, as we have hotter summers.
I intend using electric heat in the shoulder seasons, when there is still an excess, to reduce the amount of firewood (my main space heating) I have to block and split.

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Re: Electrikery...

#12 Post by llondel » Fri Sep 23, 2022 9:41 pm

VP959 wrote:
Fri Sep 23, 2022 8:40 pm
The sizing of the panels was simply the maximum number we could fit on the South side of the roof. We could get 25 panels up there, with a thin band of slates around the edge (the panels are set into the roof, so are the watertight roof covering on that side). That gave us 6.25kWp, which turns out to be around 30% more over the course of a year than we use. The bugger is that we generate most power when we don't really need it, so we stuff as much as we can into the cars, run the aircon in summer just to use the power, and then end up buying power from the grid(albeit overnight when it's cheap) in the winter.

There was no science involved, as the cost of the panels wasn't that much different from the cost of the slates we'd have had to buy (it was a new build). I'm in the process of adding another 2.4kWp of panels to form a car port, again because solar panels weren't much more expensive than roofing panels, so it was a bit of a no-brainer to fit them.

We don't get paid a lot for exporting energy to the grid, about 1/6 of the cost of buying electricity, so hardly worth the effort. Definitely worth storing the excess in batteries or the cars, though. We both run EVs now, and haven't paid to charge either of them since the end of March. Saves a bit of cash, but also gives the government the finger, as about 70% of the cost of fuel here is tax and duty, and at the moment the government haven't found a way to tax people running their cars for free from their own solar systems.
I sort of operated on the same principle, I asked "how many can you fit up there?", which turned out to be 34 panels, so we're closer to 8kW peak. California has rules about how close to the edge, or to roof openings, you can place panels. The hard part was finding an installer who'd put them on a tile roof without insisting on replacing the roof with something else too, and we eventually bought the system as a DIY install and then found someone local who would put them up, probably cost around $28k total, most other quotes were closer to $40k. Then there was the 30% federal tax credit so it effectively cost us about $20k. Given that even when it was installed we were paying typically $300/month for electricity (computers 24/7 plus pool pumps plus kiln adds up) and now we pay them less than that per year, it's going to pay for itself quite quickly, especially considering the increase in costs.

It's definitely not good economics if we were exporting power, but as I mentioned, California has a Net Energy Metering scheme where the meter runs backwards when we're providing them power, and we settle up once per year for the difference, so we don't need to worry about cost per kWh most of the time. If they were going to change this (and they keep trying) then I'd be giving serious consideration to batteries and not let them have any of it. At the moment it's the best of both worlds - they save transmission losses supplying power to our local bit of the network and we get full benefit of the power generated because stuffing it into a battery wastes some of the energy as heat.

Having said that, if it wasn't for the really hot spell a few weeks back, we'd probably be ahead this year, but the aircon was on for some of that period.

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Re: Electrikery...

#13 Post by llondel » Fri Sep 23, 2022 9:51 pm

Fox3WheresMyBanana wrote:
Fri Sep 23, 2022 8:49 pm
Thanks.
What is your typical energy usage in kWh/day?
Do you happen to know your sunshine hours/year?
Is your roof exactly south?Slope?
I have a hot tub that will make use of the summer energy excess!
I also use a/c, as we have hotter summers.
I intend using electric heat in the shoulder seasons, when there is still an excess, to reduce the amount of firewood (my main space heating) I have to block and split.
A typical day we use about 45kWh, based on what it used to be before solar.
We get about 2000 hours of sunlight per year in San Jose according to Dr Google, although last year and the one before it was seriously degraded by wildfire smoke. This year we've been lucky and not had so much of it, which might be why we're close to break-even on power generation. Lack of ash accumulating on the panels helps too.
Our roof is more SSW, as I type the sun is broadside on to the roof, 14:47PDT.

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Re: Electrikery...

#14 Post by VP959 » Fri Sep 23, 2022 10:00 pm

Ouch! Those prices sting a bit. In 2014 our 25 panels, including installation in roof trays, all the edge flashing so the roofers could lay the slates around them OK, the inverter and the wiring into the house supply, cost us a bit over £8k, so around $13,200. There was no extra tax to pay, and we saved around £2,500 in the cost of slates for the roof, plus the labour to fit them. At a guess, fitting solar panels cost us maybe £4,500 more than if we had fitted slates to that part of the roof. I think our system paid for itself after about 6 years, so the energy we've generated over the past couple of years has been effectively free. On top of that we get paid a subsidy from the government, the Feed in Tariff, that pays us, on average, about £1,000 per year for 20 years from the date the system went live, so that has paid us around £8,000 so far, tax free, over and above the value of the electricity we've generated and saved.

The battery system I installed about 2 years ago cost about £6,000, so was paid for by the subsidy we got for fitting the solar panels. The batteries save us at least 60% to 70% of our (relatively small) electricity bill. The battery system also has an unexpected benefit, as it acts like a levelling system in cloudy weather. Means I can charge one of the cars at a slow rate, with the house battery ironing out the peaks and dips in the solar generation, filling in when a cloud passes over and then topping back up when the sun comes out. This was very much an unexpected benefit, and adds a lot of value here when the weather can be very variable in the short term.

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Re: Electrikery...

#15 Post by Fox3WheresMyBanana » Fri Sep 23, 2022 10:44 pm

Very interesting, thank you.
My electricity usage is currently 10 kWh/day, but there's only me here most of the time. I can cut that by 3/4 easily in a battery-only situation, so reckon I have 5 days at least in a grid-out/cloudy situation.
I have six 230W panels in storage (1.4kW peak), and a 11kWh (to 50%) set of batteries.
Cost very low as I got a set of case blemished batteries out the back of the factory loaded onto my truck, cash, no questions asked, squire. Similar with the panels.
I shall be building my own 2-axis tracker using car seat motors and a microcontroller.
The inverter, solar controller and wiring were the expensive bits, as these are all top notch from the USA.
My place gets about 1900 sunshine hours a year, and crucially about twice the sunshine hours as the southern UK in the coldest months.
I'm not going to speculate on the improvements by having a tracker - I will install it and see!
Repayment time will be quite high - possibly as long as 12 years, so I am almost in the situation of paying the money to the solar suppliers rather than the power company. This is a consequence of Canada having cheap mains power.
Since it's mostly hydro, our bills have barely moved during the recent energy crisis - 2% increase, I think. What I will get is the ability to live normally during an outage, rather than the somewhat rudimentary standard running off a generator.

My main emphasis has always been to reduce the energy used in the first place. As I have to completely refurbish this 100+ year old house, I am upgrading insulation, improving window placement, etc.

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Re: Electrikery...

#16 Post by VP959 » Sat Sep 24, 2022 8:17 am

To give an idea of the increase in tariff here, almost all our grid power is drawn at the cheap rate, overnight. Up until 1st April this year that was costing 7.6p/kWh, plus a standing charge of 23p/day. The price increase in April took the electricity price from 7.6p/kWh to 18p/kWh and the standing charge from 23p to 42p/day. A pretty hefty increase, and it's about to rise again on the 1st October. Our heating and hot water is going to cost us well over double this winter, perhaps as much as three times what it cost last winter, so every bit of grid power I can save makes all the difference.

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