Solar power

All the different ways of solving the shelter problem. To be static or mobile? Roots, legs, or wheels?
sky
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Solar power

Post by sky »

How should an ere person decide whether to add solar power to their home? I see a few aspects:
1. Financial return on investment
2. Impact on climate/environment
3. Insurance against power outages and grid failures
4. Potential vehicle charging capabilities

Are there any other factors to take into consideration?

rube
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Re: Solar power

Post by rube »

#3 works only if you're setup is capable of "island mode". This is not typical (in my region) yet. Can be done, but requires the right hardware.

#5 If placed on the roof: creates a buffer between the solar panels and the roof tiles, such that the house inside stays (slightly) cooler.

theanimal
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Re: Solar power

Post by theanimal »

#6 Suitability for local climate/home environment (ie how much sun does your location/where you're going to put the panels get)

sky
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Re: Solar power

Post by sky »

#7 Expected longevity of residence in that location.

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mountainFrugal
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Re: Solar power

Post by mountainFrugal »

#6.5 seasonality of sun resources (partial shade from trees still worth it?)
#8 cleaning/dusting/maintenance schedule/willingness

sky
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Re: Solar power

Post by sky »

Is solar power actually good for the environment?

jacob
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Re: Solar power

Post by jacob »

sky wrote:
Fri Jul 15, 2022 3:42 pm
Is solar power actually good for the environment?
Second-most important question to be resolved during the 21st/22nd century.

sky
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Re: Solar power

Post by sky »

How would a solar installation affect the value of my home?

How would a solar installation affect my property taxes?

Should I maximize the area of solar panels or just enough to cover my needs?

Grid tie or off grid battery system?

Would I be better off investing the money than buying a solar installation?

RealPerson
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Re: Solar power

Post by RealPerson »

sky wrote:
Fri Jul 15, 2022 9:05 pm
How would a solar installation affect the value of my home?

Grid tie or off grid battery system?
Also consider the cost of homeowner's insurance. At first our insurance company declined to insure our house with the panels.

Think about the fire safety of your battery setup. A lithium ion battery fire can be difficult to put out. Maybe ask your local fire department for their recommendations? I would not want something like that inside my garage.

AxelHeyst
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Re: Solar power

Post by AxelHeyst »

I have no data, but my sense is that PV system battery fires are very rare, unless you get a complete moron to wire it up. You should be able to sleep well with a properly installed system in your garage. Most people sleep well with a rolling potential fuel air bomb sitting in their garage.

rube
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Re: Solar power

Post by rube »

RealPerson wrote:
Sat Jul 16, 2022 1:19 am
Also consider the cost of homeowner's insurance. At first our insurance company declined to insure our house with the panels.
Clearly something to check. In our region it is no issue at all.

In general, most of these considerations seems to be very local/regional.

sky
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Re: Solar power

Post by sky »

Generally, the first step in an ere approach is to reduce expenses, and in the context of energy, reduce electrical use. By reducing electrical use, one reduces the investment needed in solar panels and batteries.

However, one also has to consider that one day the house will be sold to others, possibly within the service life of the solar installation. Also, one may live in a house with other people who prefer a more energy intensive lifestyle. So choosing a system for a house is not just a personal choice, housemates and future residents are also affected.

sky
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Re: Solar power

Post by sky »

A person who travels and is away from home derives very little benefit from their investment in a solar system.

NewBlood
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Re: Solar power

Post by NewBlood »

jacob wrote:
Fri Jul 15, 2022 3:45 pm
Second-most important question to be resolved during the 21st/22nd century.
Hi Jacob, can you elaborate on this?

theanimal
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Re: Solar power

Post by theanimal »

I can't speak for the lithium batteries but the traditional lead acid deep cycle batteries are very safe and like @AH said, I don't know how you could have a fire without someone really screwing up the wiring. The non lithium batteries still dominate the market and what the vast majority of people use for solar panels because of cost. My $800 batteries would be 10x the cost if I wanted to use lithium. Ours rest underneath our couch, which also happens to support our bed. We have no concerns at all about this setup. When I lived more remotely, my neighbors had similar setups and had their batteries tucked away in the main living areas of the home. The batteries' original purpose was for small spaces like small cabins, RVs, and boats.

We are 100% solar powered for 8 months of the year (generator for the rest) with no tie in. Solar power is very beneficial for us even when we are travelling because there are frequent power outages in this area, mainly during the winter but occasionally during summer. We have at least one chest freezer in use at all times and being independent of the grid gives us the security to know that we can preserve our food even when we are gone and the grid power goes out.

I think if one thinks too much of future use of the house you risk falling into the "investosis" thinking that @Ego described here viewtopic.php?t=12124 . I don't think what other people in the future might think is the right lens.
sky wrote:
Sat Jul 16, 2022 8:59 am
Generally, the first step in an ere approach is to reduce expenses, and in the context of energy, reduce electrical use. By reducing electrical use, one reduces the investment needed in solar panels and batteries.
This point is very much understated in those interested in solar. It seems that many who get solar panels just get a massive array and battery bank without any thought of reducing their electrical needs. They want to be off grid and have the status of being greener, but I would have to imagine the environmental benefit is probably marginal. It also probably doesn't make much sense from a monetary perspective. My neighbors in the Arctic had a ton of back issues of Home Power magazine that they lent me to learn about alternative systems when I was first setting up my system at the cabin there. The old issues had a lot of experimental designs and suggestions that centered around reducing fossil fuels and impact on the environment. By the issues in the late 2000s, early 2010s, the theme had shifted to just making normal McMansions off grid with a plethora of articles like, "Look at this 50 panel and 36 battery bank that powers this ~2,500 sq ft home!"

rube
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Re: Solar power

Post by rube »

As I said before this is very regional. But in our case, with the investment of about 12.5K euros in solar panels in 2020, we have fixed our energy bill at least for about 10 years till 2030. That is, in 2030 our energy bill will be maximum 0 euro's. This year I expect we even come out at -4000 euro (neighbors will pay around +3600 euro right now due to the high energy cost!). But it will be different per year, depending on what the feed-in fee is at that moment. The feed-in fee is now very high, but even if this becomes very low, the bill is probably still 0. After 2030, who knows what the rules at that time are exactly, but we will still better of than without solar panels and at least 9 months of the year the bill will be 0.

In any case, when I put 41 solar panels on our roof, some people called me crazy and didn't understand why I even put panels on the north side of our roof. I did it because I could, it was not a purely a financial motive at that time. Just wanted to generate as much as possible electricity and the cost of 12.5K was well worth it to me.

Add: after I posted I read the additional comments of theanimal above. I agree, and especially if you are off-grid, just putting as much solar panels as you on the roof and as much as possible batteries is not cost or environmental efficient. So even though I did put on as much solar panels on the roof as possible, we watch our usage quite carefully. The surplus we have simply goes to the grid and is basically immediately consumed by our neighbors, who don't have solar panels. So there is no "waste" of electricity.

theanimal
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Re: Solar power

Post by theanimal »

Another question: What is the primary fuel source for the grid in my area?

RealPerson
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Re: Solar power

Post by RealPerson »

AxelHeyst wrote:
Sat Jul 16, 2022 2:24 am
I have no data, but my sense is that PV system battery fires are very rare, unless you get a complete moron to wire it up. You should be able to sleep well with a properly installed system in your garage. Most people sleep well with a rolling potential fuel air bomb sitting in their garage.
Remember the ship that had a bunch of luxury electric cars on board that were on fire. The ship sank in the Atlantic Ocean, presumably putting out the fire.

The concern of fire came from a firefighter. They know what to do with a gasoline car for but the lithium ion battery fires cannot be extinguished. Fuel does not typically self combust without a spark or flame. This is contrary to lithium ion batteries, that can spontaneously self ignite. Everyone has to decide what their comfort level is, but it should be at least something to consider. There is a reason airlines today do not allow these batteries in the cargo hold of an airplane.

Traditional lead acid batteries do not have this self combustion problem and are very safe (provided the hydrogen gas vent is patent of course). The issue with lithium ion and fire is related to the flow of electrons in that type of battery chemistry IIRC.

AxelHeyst
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Re: Solar power

Post by AxelHeyst »

Ah, I concede the point for the case of lithium batteries, quite right.

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Re: Solar power

Post by Bonde »

Firefighters in Denmark have procedures to handle fires from lithium batteries. Fortunately fires are very rare and the batteries are getting safer, more effective and with less environmental burden. They are not perfect but better than fossil fuel combustion engines. They also catch fire, are very ineffective energy wise and the environmental burden is unsustainable.
Besides the ”change is bad” attitudes, a big problem is also the lobbying from fossil fuel companies and traditional car manufacturers with more or less secretly sponsored news articles and SoMe posts about what is wrong with renewable energy and electric cars.

That said, we don't have a home battery for our solar panels. We have a stable grid in Denmark. Batteries are quite an environmental burden so better to use the grid which is reasonable greenish where we live. Mostly we can charge our car during sunny hours which is by far our most power consuming entity (we don't have aircon and use wood pellets for heating).

Concerning solar we bought our house with 4kW panels. Our car can only charge with max. 3.6kW so higher kW panels don't make sense for us.
If the panels malfunction we would most likely buy new ones if they cannot get fixed. I would be very surprised if a return of investment analysis wouldn’t support purchase of new panels. But if the grid is cheap and supplies power with low environmental burden (a lot of wind power are getting installed in the Danish oceans), we would most likely be OK with dependency. It would also depend on other factors e.g. political stability.

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