Any advice on Home Solar?

[Jo]

I have just remembered one issue with panels: Feral Pigeons (Rock Doves) like nesting beneath the panels and have been known to damage the high voltage cables as they scramble around underneath.

We only get Big Fat Wood Pigeons round here. Their idea of a nest is two twigs balanced on a branch fork in a tree.  No self respecting Wood pigeon would bother with the effort of making a real nest 

Jo

[Mike R]

Timely discussion, I just looked into this here in Ottawa, ON, Canada and there are other considerations that apply so you need to do your homework on your particular city, state/county/province, supplier,  or country. 
In my case, similar to the UK there is a max that you can reasonably /cost effectively feed back to the grid - 10KW (no max time limit).  Over that requires special engineered (read $$$$$) analysis. 
They also pretty much did away with the biggest incentives. Now the best you can do is effectively reduce your total consumption to 0KWh by generating all day and using that credit at night or during low solar generating time.  The biggest catch is that you are still connected to the grid and about half my electricity bill is made up of "delivery" charges that will still be applicable.  So that really stretches out the payback period.
The above scenario is typically called a grid-tie system and has no batteries.  You can add batteries, but as you've already reduced your consumption to 0KWh it doesn't have any payback, just backup power availability (a definite consideration for some locations outside the city).
Also, to Jo's point - some system designs require "squirrel guards" and others don't.  An additional cost and installation effort.

[Art K]

Kim,
I'm in Madison Wisconsin. My wife and I added solar in January 2023 after selling my parents house. In 2022 there were incentives to add solar that were supposed to go down as of the end of the year. In reality the 26% went up to 30% returned. They also had a contractor replace the roof. The shingles were on the 20 year point of a 25 year lifespan but the ridge shingles were bad. this cost was added into the system cost because it was done at the same time. Our system was more expensive due to the components being made in the US. That wasn't necessarily why we chose it. Most solar installers here were extremely busy and only 2 paid enough attention to us to give us an estimate, or return our call. We chose the one that said they could do the job by December 31st.
Our house has a hip roof so our 9.6 kW system is split up 6 panels east facing, 6 west facing and the remaining 12 south. They tried to build a system that met our power usage. the local power company MG&E pays us for what we don't use and add the rest to the grid. It's nice in the summer when production is at the peak we build up a positive on our bill which helps offset the natural gas heating bill in the winter. We considered getting a battery backup BUT it was an extra $20,000 and we figured they would get cheaper and better at a later date.
Enough for now my eyes are rebelling, telling me to stop looking at a screen!
Art

[Art K]

Kim,
Just thought I''d let you my most recent Madison Gas & Electric bill was 72 cents! That covers heat and water heater.
Art

[Kim]

Wow!  That's pretty impressive!

Do you not have to pay a fixed fee to be connected to the grid?  I've heard the grid fee around here is something like $12-13.  So 72 cents seems amazingly low!

Kim

[Art K]

As the summer goes on I build up a surplus where MG&E owes me. Power generation goes down in the winter, especially when it snows. Heating bill in the winter can be 300 or more but we don't generally get a full one till December. I would have to look at the details to see about grid connection fees ect.
Art

[Kim]

Ah, so you actually get to sell power back to the power company?  That's nice.

Out here, we have "net metering," where you can make more power than you use, or use more power than you make in any given month.  But at the end of the year, they total it all up, and if you used more than you made in total, you pay for that part, and they'll credit or debit your account by that amount. But if you made more power than you used in the year, you get no money back.  And you have to pay a grid connect fee every month.  Basically, you can only offset your electricity usage over the year; you can't make money on power generation as a residential customer.  My understanding is that this is because the power company can't count on your power, nor does it come when they necessarily need it.  So it kinda makes sense to me.

Kim

[Jo]

Quick comparison with last week ....

The sun is out, the temperature is 12 degrees C and my Solar array is generating 3970W  That is not bad for a 15 year old 4KW array which needs washing.


If you can "swop" the units of generated solar power with mains power when you need and only pay (or be paid) for the annual balance that is probably the best deal you are going to get 

Jo

[Twizseven]

Unfortunately I dont think I could fit solar as my neighbour has 18-25metre tall trees which prevent my house (and garden) let alone the roof getting any sunlight from around 13:00hrs onward.  There is also a gigantic Oak tree in other neighbours garden which stops majority of sun from around 08:00hrs - 12:00hrs.

I am interested to know how many of you with solar panels have a three phase power supply into your workshops and how this interacts (connects) with your solar.

Colin

[tghs]

my shop/carrige house build has been desiigned with solar in mind,, saltbox style roof with the angle adjusted for our location,, footprint sited for best collection..

[Jo]

Just been pricing up a little EV for use as a home solar storage battery... To find it is cheaper to buy a brand new car than the equivalent Tesla Powerwall boxes. 


The Hyundai Inster I was looking at is an all electric car with 4 usable seats, has a pathetic boot space (even Minx has a bigger boot  ) but importantly a 49KWh LI battery. They claim it has a range of over 200 miles  I said I will assume 100miles in winter, taking into account the not lower than 20% charge and not above 80% for maximum life on the battery and wanting to run the HVAC to keep warm.  The cost? £23K, equivalent power Tesla Power wall size is over £30K. Other EVs are more expensive 

Out of interest I got quotes for insurance around £250 full comp for the Inster. (Twice as much as Minx but 2/3 of Woody's Insurance).


I was promised that it is compatible with using it as a house solar battery. 

Jo

P.S. I noted that the garage has dumped  no longer sells the BYD EVs they were selling last year. I should have asked why 

[crueby]

Thats... nuts? genius?     (the pricing is nuts, using the car is genius)
Very clever to even look at it that way! 

[Vixen]

Just been pricing up a little EV for use as a home solar storage battery... To find it is cheaper to buy a brand new car than the equivalent Tesla Powerwall boxes. 

............ The cost? £23K, equivalent power Tesla Power wall size is over £30K.............

...........I was promised that it is compatible with using it as a house solar battery.

Jo

Thinking about the idea of using a solar storage battery to run the HVAC to keep warm during winter. Will the solar provide enough spare power when the outside temperature and sun shine are at their lowest level? Have you calculated the pay back period for your 49KWh solar storage battery (on wheels)? Or do intend to use it mostly as another car?

Mike 

[Jo]

I was just killing time while they tinkered with Minx 

I was expecting starting prices around £30K for an EV based on the Tesla power wall prices and was very surprised to find that one at the much lower price. You will have to add a converter/manager to transform the DC battery voltage into mains wobbly volts but that should be under £2K.

I was looking at it as a potential replacement car for my Father who has a nasty habit of driving right up the backside of the car in front  and honestly in his mid 80s there is no way he would react in time if the other car braked. These modern cars won't let him do that so they will force him to (possibly) drive more safely. Ok so it is not an amazing car but if you were suffering from the usual challenges of old age (bad knees or hips) it would happily allow you and three friends to get out and about. And importantly you can plug it in using a standard plug to charge and because you are not fast charging it is safe to charge it in your garage. And using the App  you can use main electric to power heating the car so saving your valuable LI battery charge.

A point to note: LI batteries do not like charging when it is very cold so this idea of faster charging and having to leave the car outside is not that sensible in winter 
-----

You can use the EV in summer to store excess solar but in winter you would need to charge by mains. A good inverter would enable you to power your home using cheap stored EV electric or operate your home "off-grid" from it during power cuts (and would switch back on when the mains power was restored). In a few years these EVs will be half the new price and in the UK  someone who likes writing a bit of software could use it to buy cheap to charge the car battery and sell those electrons back for more money to the grid.

 Jo

[AdeV]

You will have to add a converter/manager to transform the DC battery voltage into mains wobbly volts but that should be under £2K.

Any vehicle that supports V2L (Vehicle to Load) already has a wobblemaker built into it. You would need some kind of box to be a "load" as far as your vehicle is concerned, but inject that power into your home, matching the grid frequency etc. Also, you'll be limited to around 2-4kW from the V2L link depending on the vehicle. 

V2H(ome) and V2G(rid) are still immature technologies, but are coming.

And importantly you can plug it in using a standard plug to charge and because you are not fast charging it is safe to charge it in your garage. And using the App  you can use main electric to power heating the car so saving your valuable LI battery charge.

I charge my EV that way (via the "Granny Lead") - it takes a while to bring it from 20-80%, but as I don't do a lot of miles these days, that's typically something I do maybe twice a month. Heating the car from the car's own battery isn't anything like as calamitous as it used to be (e.g. in an old Leaf or Zoe). And if your car has a heat pump, you'll barely notice the power draw.

A point to note: LI batteries do not like charging when it is very cold so this idea of faster charging and having to leave the car outside is not that sensible in winter 

All modern EVs have active thermal management. So even on properly cold Canadian winter days, they're happy to charge. If you don't run a pre-condition (i.e. pre-warm), they'll be slow at first - as they get warmed up - but as soon as there's enough warmth, you're off. Again, older EVs like Nissan Leafs and Renault Zoes - which did not have active thermal management, will suffer.

In a few years these EVs will be half the new price

They're already there! You can pick up a used Hyundai Ioniq 5 for less than £15k, that will do up to 3.6kW V2L. And you get a pretty cool car to go with your big battery too...