Going solar: considerations and numbers

p4ul · Apr 26, 2023

Shabbaz
I've renovated my house. Triple glass, isolation, heatpump (still on the waiting list, takes more then a year to get one) and 8 solar panels. I bought them for eur 5300 and they should generate around 3200 kwh. That's what I use every year. I live in Amsterdam by the way. I got EUR 900 back from VAT. And the energy company pays me for the the solar energy I dont use and give back to the network. Energy prices were crazy last year because of the war in Ukraine. In december 2022 I paid more then eur 1000 for gas and electric.

With you all the way! I installed 13 x .375kWh panels and 2 x 5.2 kWh batteries, this month, my electric will drop from £140 to £40 per month.
They are called solar panels but you don’t need full Sun cloud on mine today in South England.

Oh, and that is without the feed back tariff payments I will accrue for winter use.

If anyone wants to look into solar I recommend a look at Octopus Energy, UK based but going world wide.

BlackTalon · Apr 26, 2023

In my experience working on projects where solar may already be existing or is proposed, and listening to the M/E/P engineers, the mechanical/ interior parts of the system will have shorter lives than the panels themselves. So when figuring overall costs of ownership that should be taken into account. When thinking about eventually doing something at my own house, springing for batteries would be a must. And unfortunately the roofs slope towards the east and west, which will impact the system effectiveness.

pdxleaf · Apr 26, 2023

Batteries would be nice, as it means power when the grid is down. But that can be significantly more expensive. Plus there's more maintenance, which varies on the type of battery. Batteries don't last as long as the panels, etc.

While we do lose power on occasion (freezing rain in the winter, high winds from the Pacific or down the Columbia Gorge), it is cheaper for us to have a separate small generator for the few occasions where there is no power. Someone living more remotely or trying to go offgrid might benefit more from batteries than someone in a city like us. But i wish i had batteries when we lose power.

There will come a day when batteries from electric cars need to be replaced due to lose of capacity. Nissan and Tesla have mentioned reusing these batteries for home storage. Depends on cost on how attractive that will be. It also seems a ways off.

BlackTalon · Apr 26, 2023

Around where I live power mainly goes out during storms. So at a time when solar generation will be about zero. And it's also the time sump pumps need to run to keep basements from flooding. The 12v car battery 'watchdog' systems can help keep the sump pump running for a bit, but lose power for a full day or two and you need a Plan B.

vbrad26 · Apr 26, 2023

We did solar here at the office a few years ago.

Also have some panels at the house strictly to heat the pool.

Syzygy · Apr 26, 2023

Re: batteries. There has been some pretty impressive advances in Nickel Zinc cell technology. They fail closed, so when used in series/string, the failed cell will simply stop helping the rest of the string, but won't actually make the whole string useless like cells that fail open. Not to mention the risk of thermal runaway when fail open cells give up the ghost.

I'd be interested to see when NiZn cells make the transition from Data Center industry to home backup strings. We're seeing the profiling data indicating 15-20 year life, so that's another big consideration in TCO. Seems to me to be a fantastic fit.

ghce · Apr 26, 2023

I think we tend to get too caught up in the latest greatest battery technology.
With all the great advances in the last 20 years in cell types such as greater power density, charge and discharge rates etc, whilst they are amazing they are woefully unreliable in extended time scales.
Sure they do everything you ask for but they will end up costing you in the short to medium timeframe both dollar wise and time and inconvenience.

Some of the oldest technology whilst not very efficient pays long term dividends based solely on reliability and so long as you can scale your battery KWH capacity to suit your needs be it off grid or supplemental you can sleep walk to power security till the day you die.

One of the older technologies is the nickel iron cell, these suckers will last 100 years with very low maintenance, power density is a bit sucky compared to later tech but who cares when you can have 100% reliability.

So long as you scale your solar panels to overcome the inefficiency and self discharge rates.

In my youth I recovered a bunch of these cells from a long abandoned coal mine where they were used to power miner's headlamps for underground work, they were at least 50 years old at that point, all I did was replace the old electrolyte and charge them, they were still at 110% of face plate rating, used them for 20 plus years as bench back up supply until I shifted house and left them behind.

ghce · Apr 26, 2023

I have no connection to this company but here is a brief low down.

https://www.ironcorebatteries.com.a...Edison Nickel Iron,and still being used today.

BlackTalon · Apr 26, 2023

vbrad26
We did solar here at the office a few years ago.

That helps reinforce a very concrete solution. Do the wires mesh well with your operation?

vbrad26 · Apr 27, 2023

BlackTalon
That helps reinforce a very concrete solution. Do the wires mesh well with your operation?

You nailed it.

ghce · May 8, 2023

Looking thru real estate adds I often see the comment that they already have panels 24 Plus but you just need s battery to get off the grid entirely, so it would appear the current bugbear is the cost of storage to kick state providers out altogether.
Other than the ultra reliable NiFe cells I posted on above there other ingenious ways to generate electricity once the sun departs but powered by the sun in day light hours.
Its quite amazing to me that some of these mechanical systems haven't been explored in a commercial manner. examples are weights lifted in day light hours and let to fall by night on demand to generate electricity be the weight concrete or water, or heated masses of water or cast iron where the energy can be extracted by thermo couple or similar as needed.
All really old ideas that have been swept under the carpet in the rush for battery tech at high price.
Sure there are penalties to pay efficiency wise with double conversions and efficiency will suffer but these are known factors that are easily overcome when scaling the night time energy extraction and are of a low tech ( cheap) nature.

BlackTalon · May 8, 2023

@ghce look for this thread on audiosciencereview dot com:
Grid Storage Systems for Renewable Energy - Technology and Projects

There are a few posts about moving mass, etc. There are also some people on that forum who work on development of some of the storage system technologies.

Vercingetorix · May 8, 2023

Certainly salt towers rule the cool factor.
.

ghce · May 8, 2023

Vercingetorix
Certainly salt towers rule the cool factor.
.

When out ancestors discover those artifacts long after we have annialatetted ourselves they will say those 20 th century people built massive sundial clocks and monitored the celestial bodies in some cult religious ceremonies and how they transported those materials which were foreign to the area over vast distances to build these religious artifacts to perform pagan rituals.
What goes around comes around 😁

Vercingetorix · May 8, 2023

ghce
When out ancestors discover those artifacts long after we have annialatetted ourselves they will say those 20 th century people built massive sundial clocks and monitored the celestial bodies in some cult religious ceremonies and how they transported those materials which were foreign to the area over vast distances to build these religious artifacts to perform pagan rituals.
What goes around comes around 😁

It’s a huge bird barbecue.

p4ul · Oct 30, 2023

p4ul
With you all the way! I installed 13 x .375kWh panels and 2 x 5.2 kWh batteries, this month, my electric will drop from £140 to £40 per month.
They are called solar panels but you don’t need full Sun cloud on mine today in South England.

Oh, and that is without the feed back tariff payments I will accrue for winter use.

If anyone wants to look into solar I recommend a look at Octopus Energy, UK based but going world wide.

Well, October bill in today and since installation in April I have paid my electricity supplier………..nada, nothing, bugger all. In fact they have paid me a credit of £120 so my previous £140 downed to £40 a month estimate was wayyyy off.

The worst 3 months are coming but as I set up a £50 standing order payment in April expecting a bit back after a year my account stands over £500 so come spring I will cash in.

The summer in the UK was mixed, we had a really hot & sunny burst but also a lot of the usual grey, I am amazed at the amount of charge I get on a cold sunny day, they perform better when the air is cool.

How is yours performing @Shabbaz ?

hen · Jul 25, 2024

Works great!

Stewart A · Jul 25, 2024

Greetings - I'm certainly NO EXPERT in terms of solar power/energy but this has been my experience to date. I recently had panels placed on my home - 16 panels for a 2100SqFt home and also had a back-up battery as well. I'm still waiting for a full year to assess how well my electric bills will fare; however, the previous two months (May and June) have been incredible, we had $00.00 bills, primarily due to not running the air and sending back power to the grid. When I review July, which has been fairly warm in Southern CA, we are at 49% grid dependency and we are sending back to the grid a similar amount that we use. Now granted, we are sending back energy during the day and this is at a moderate $rate but we have been running our AC during the day and still sending power back to the grid. SO, we shall see how my bills will be during July and Sept/Oct - notoriously hot months. When I signed up, the energy company indicated that the system would be paid off in about 9-10 years based on our previous usage. Ominously, our electric company (SCE) announced that they plan to increase electricity costs about 3.5% yearly through the year 2030. Electricity costs will be crazy high. We shall see how this all works out.

p4ul · Jul 26, 2024

@Stewart A I don’t know the US(?) market but here in the UK, as electric prices rise so does the amount paid for solar production meaning that it almost does not matter! Of course it will depend on the company you deal with, here I am with Octopus who do a superb job and I know they do have a US presence?
My payback was estimated at 8 years and I should hit that but after having installed a year ago the money has gone and it has become secondary in my mind to the greater benefits to the planet and thence my grandchildren.
Further to my previous post I got back £650 after a year so my 12 - £50 month standing order returned, free electric for a year (or rather pre paid from installation cost!) without solar my annual bill would have been pushing £1500. I have dropped my monthly to £10 but that is just insurance for my supplier really to know I won’t stiff them!

p4ul · Sep 11, 2024

Wherever you live, get at least 3 quotes and check with someone who has solar installed local to you to try and obtain unbiased advice.

Some solar suppliers are the timeshare salesmen du nos jour!