Solar power wiki

[John J]

Looking idly at the wiki I'm not seeing much on solar panels, inverters or addition of batteries to systems. Is my searching at fault or is there scope for a new section?

[Smolley]

More information on Amazon.

[TimW]

I also am looking for info.

I am planning to rebuild a detached garage which currently has no power at all. I need to design an electrical system which will keep a car charged for commuting, presumably a combination of solar panels, wind turbines, static batteries and a mains connection to make sure I can charge a vehicle overnight, only occasionally resort to mains usage and otherwise feed-in any excess.

It should be perfectly feasible, no? But it needs the right specs and hardware and needs to be costed.

TW

[Theo]

Probably. A lot of the info is international, although there are some local details (DNO connection etc). Some UK localisation could be useful. I'm not sure if there's an existing resource that it's better to point people at for the non-local info.

My suggestion of the go-to place is diysolarforum.com but a lot of folks there are US-based. eg I was trying to find some 'class T' fuses which they recommend over circuit breakers for DC, but 'class T' is a UL standard and they're impossible to buy over here. Once I'd worked out that it means 'high rupturing current' (dozens/hundreds of kA) and I'd found the HRC fuse section on Farnell, it made a lot more sense. Turns out the corresponding UK equivalent is 'BS88' industrial fuses, which are easily available.

Should be doable, depending on what you want.

Perhaps a way to do it might be to agree what the topics of interest are, perhaps posed as questions here. It's much easier to answer questions than it is to sit down and write a book on the subject :)

(I'm currently building a battery system and have solar in planning, so can fill in some of the gaps. However I'm learning as I go, so it would ideally be checked by somebody with more experience)

Theo

[Andy Burns]

searching for "type T" rather than "class T" seems to get better results

[John Rumm]

There is some stuff on solar thermal, but not much on solar PV...

Very much so... One problem with the wiki currently is there are only a limited number of authors who create new articles, so unless a topic appeals to one of them, it does not get much coverage.

[Theo]

I think they're different: 'class T' is a UL standard for high rupturing current. 'Type T' seems to be a time delay fuse:

and it seems like both can refer to industrial fuses.

BS88 is a much easier standard to find and a lot cheaper to buy in the UK.

Theo

[John Rumm]

A small amount of info on those here:

[Animal]

I only remember one article on solar thermal panels. Write one if you're up for it.

Solar & wind will deliver a % of the time. If you want to ensure it gets charged you'd also need batteries several times the capacity of the car one. It would be silly expensive.

[Peter Johnson]

Rig one of these, or something like it. (I got one after I had to call out the AA with a flat battery twice during 2020. Leave it connected all the time, but I leave the car outside and it faces south.)

[John J]

If I had sufficient knowledge of Solar panels, inverters and batteries I'd have been happy to make a start. However as I haven't I thought it would be worth looking in the wiki. For what it's worth I've got a "professionally" installed 4kW grid tied system that has yielded higher rate FIT payments. Currently I'm thinking it might be worthwhile to investigate the current maximum grid tie arrangements and best rates of payment for export of any unused generation or the economics of installing batteries and no export. Maybe even run part of the house independently of grid connection. All this before looking into arrangements/mounting of panels located elsewhere as the roof is already full.

[Vir Campestris]

If "charged for commuting" implies it won't be there in the day the solar panels are a waste of time and money. Unless you can find a cheap set of batteries with more capacity than the car.

You can't of course rely on wind either. I think you'll be using the mains a lot.

Andy

[TimW]

Not at all. With the price of fuel and of mains electric high and likely to stay high and the price of panels and batteries likely to be going down a moments thought will tell you that the economics of it are sound. There might be times when you use the mains but a little planning and a little flexibility will help.

There is a lot of misinformation about, for political reasons. Sadly in these times you need to be careful who to trust and believe.

TW

[TimW]

They are expensive but a high capacity battery for exactly that purpose is a standard requirement and an off the shelf item. Nissan car batteries can be given a 'second life' by design as static charging batteries. So when you upgrade or replace your car batteries they are part-exchanged, refurbed and re-used.

The cost of a tank of petrol being what it is, and renewables being free once you have the hardware in place - the cost is relative!

TW

[Robin]

More than I can think through in a moment! ISTM crucial facts are (a) total net cost of what your home system can generate plus the cost of anything you still have to buy from the grid and (b) the total cost of buying it all from the grid.

Easy enough to DIY an investment appraisal. Not so easy to get the assumptions right about e.g. output, life expectancy, maintenance & repairs, future prices for grid power, cost of money. I'd be interested to see sums.

[Theo]

I have started wiring something :)

At the moment just dumping words down, it'll need numbers / diagrams / sources etc sorting out later.

Not yet uploaded (easier to edit locally), but in the meantime useful to have a list of 'things that you would like to know about' so as to get an idea for areas to cover.

Theo

[TimW]

Yes of course nothing is ever really simple and I was being triggered after reading too much climate denier BS elsewhere.

In my case I was thinking £100 to fill the car up now, once a week every week, £5000 a year would fund a system for free charging of an electric car no problem (as long as it works).

But considerations are never purely economics. The cheapest way to get to work is probably to sell my good car and buy and old hatch back for £1000 then lift share as well, but I am not doing that.

TW

[Animal]

Don't forget replaced again and again.

'Renewables' are not free, they're the system cost amortised over the time it lasts. Feel free to offer us a costed system design, I can't believe it's going to make economic sense in most situations.

[Animal]

Even cheaper to thumb lifts, hack a random car owner to pieces & take their car. Can't recommend it though :) Money definitely isn't everything. Several of us are curious to see your system design & costs.

[John Rumm]

You could probably simplify the charging platform considerably if you just buy two electric cars. Then you can be driving one, while the other sits at home being charged without whatever solar PV is available during the day. Once it is full, swap cars.