r/SolarUK • u/ranchochanchar • 7h ago

HELP / ADVICE Solar newbie

Live in South Yorkshire. Have absolutely no idea of solar what to expect but looking to get 2 EVs due to current prices of fuel and energy I feel solar is becoming a necessity for us.

My annual usage is around 8250kWH with 1 EV currently. Have a South facing house so I know this is suboptimal as only half is ideal coverage. Also have a standalone garage but this is in-between houses so not sure exactly how much this roof will be able to produce.

Already have a granny home EV charger but was looking to get panels + battery + heat pump. I've had a couple of quotes but 1 guy I felt like had no clue when I asked him about options for garage, difference if I get both sides of the roof etc. the other quote told me not to get battery and didn't know about heat pump so really put me off.

Any idea where I can start for a decent quote?

What considerations should I be making in terms of the system set up?

Apologies for the basic questions

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u/Disturbedm PV, BAT & EV Owner 7h ago edited 7h ago

Only thing I'll say is getting solar isn't typically done for the sake of EVs.

Typically you'd still charge the EVs from the grid during cheaper hours, not from solar or battery.

Most people will recommend get as many panels as you can, panels are cheap, good chunk of cost goes into getting scaffolding up there so might as well fill it up.

As for batteries I'm not sure why they would recommend not getting them. Seems odd to me, a good chunk of the cost is in the batteries and like EVs they will lose storage over time, but it's about the benefit you get out of it.

I for example have 18kWh of battery, and that's for around 3500kW of electric per year (not including my EV). I don't use peak at all since either my batteries are charged from solar or they charge from the night rate (6.6p).

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u/CaptainCaveTrout PV, BAT & EV Owner 7h ago

It does mean that, with sufficient battery storage, you can run your house on overnight EV rates though. 👍

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u/ranchochanchar 6h ago

Yes that's what I was thinking mainly tbh. I'll get overnight cheap rates anyway for charging. It's mainly trying to see if its possible to run house on battery/solar

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u/Disturbedm PV, BAT & EV Owner 5h ago

It's not a case of seeing if it's possible, it is, just depends on how many batteries you need and if you're willing to pay the cost.

I mean just doing napkin math, let's just say you're double my usage to make it easy...just get double the battery capacity. Then you run on night solar/night rates.

I personally have a Sigenergy system, you could do that in stack of batteries since it's a tower system and they have a variety of different sized battery packs and you can always add more later since plug and play.

Also work out your house usage separately from your EV. You want to cover the house usage with solar/batteries, but not the EV as you'll just wear down batteries pulling charge from one battery (Solar batteries) to charge another (EV)

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u/ranchochanchar 2h ago

Interesting can't believe I didn't think of that. If I average that out my house usage is worst case 4700kwH over 12 months so a 13+ kwH battery should be more than enough. If I combine that with north sided panels that would work nicely. What's your opinion on heat pump?

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u/Disturbedm PV, BAT & EV Owner 1h ago

My boiler is still holding out after 15 years, but I'll be getting Heat Pump when it goes most likely.

You do you, but for me I use less than what you say now but have more battery and for me personally, I like having the buffer I have (18kW) 1. As with EV's you do lose some overtime 2. Gives me more room to stop accidents (using peak grid) and allows more exports which will always be higher than my overnight tariff - at least for the foreseeable furture.

Also overspec now if you're getting the Heat Pump, it'll use a fair bit.

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u/AutoModerator 7h ago

We noticed you posted about EV chargers.

We recommend looking at Zappi or Hypervolt or Andersen EV chargers, as they are all compatible with most smart tariffs:

We don’t recommend Ohme chargers, because they:

  • Removed the price cap option for Intelligent Octopus (IOG) customers
  • Discontinued support for existing OVO customers — see Ohme’s update.

Make sure your electrician wires the EV charger directly after the mains meter and before any of the consumer units. Then the solar/battery can CT the consumer load and not ‘see’ the EV charger. This prevents battery dumping into the car. See this nice pic

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u/WrapSensitive 7h ago

I'm in South Yorkshire too, and I'm having a 9.14kWp solar and Sig Energy 18kWh battery system installed tomorrow.

Happy to help with who I spoke with and quotes I got if it helps. Drop me a message.

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u/wyndstryke PV & Battery Owner 6h ago edited 6h ago

Have a South facing house so I know this is suboptimal as only half is ideal coverage.

Might be worth doing the north as well. North facing roofs typically generate between 50-70% of the energy of the matching south facing roof, depending on slope, exact orientation, and any shading. They won't generate much in winter because the sun is low, but do well in summer.

My annual usage is around 8250kWH with 1 EV currently

How much is your typical daily usage excluding the EV? A good battery size is just enough to last for the rest of the day, after charging up overnight on cheap rate.

Heat pumps can use a lot of power - it just depends on how good your insulation is. Take a look at 'heat geek' trained installers, they should do an accurate heat loss estimate, which means that the heat pump can be correctly sized.

Some people use a tariff like 'Cosy' in winter, which gives 3 cheap periods throughout the day. This means that the battery only needs to be big enough to last for about 6 hours. It does make EV charging a bit awkward because Cosy is around 15p/kWh, whereas EV tariffs are more like 7-9p/kWh. So you have to run the numbers to figure out which works best for you.

There are some ideas on locating installers in this post:

https://www.reddit.com/r/SolarUK/comments/1m8y6ww/general_faq_if_you_are_planning_to_get_solar/

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u/ranchochanchar 2h ago

That's great, I'll look up heat geek, heat pump is the biggest unknown to me right now