Free Powerwall Solar Panels

Ovo Energy are offering a FREE Powerwall here:-
Can someone tell me if bulb have any plans to do the same with,a) Powerwalls,b) Solar Panels c) EV charging points support.All replies gratefully received,Thanks,Regards,Ray

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Hi @redw756389,

We’re a big fan of EVs and will be releasing lots of exciting announcements throughout the year. You can read about some of the work that we’ve been doing on our blog - we don’t have any open spaces on this trial at the moment, but we’re going to be writing an update on Community for when we begin scaling it up.

We don’t currently have any plans to offer discounts on solar panels, but we have recently released our export tariff, where we’ll buy the energy that you export.

@redw756389 interesting read, though it is pretty limited at the moment. Also a point that should be clarified, these are not Tesla Powerwall 2 units, which your post title could mislead others to think.

OVO are offering Sonen batteries, which are a good German battery manufacturer and I know that in Germany many new builds are being fitted with both solar and Sonen batteries.

They are modular and I believe come in modules of 2.5kWh, in this regard similar to Tesla’s Powerwall 2, but individually a lot smaller.

In return, we’ll install a 5kWh SonnenBatterie worth £5000, absolutely free.

The free proposition makes this very tempting for those in Lincolnshire, however, for those interested in home energy storage in other regions. Here are my initial thoughts about batteries as a means to save money, based on my experiencing researching and ordering a Powerwall 2 to compliment our solar:

  • Battery ideally should cover your entire day’s kWh usage (10 - 15kWh is ideal)
  • Tied with any solar that is exporting 35% or above of it’s daily generation over at least the summer
  • Tied with a tariff, that accurately and frequently tracks the wholesale price
  • Continuous output of 5kW, bursting higher
  • 10 year min warranty with an end capacity over 80%
  • Battery should be independent of energy supplier (a little tricky currently)
  • App that allows scheduling your peak, shoulder and off-peak tariff times
  • Provide backup power during grid blackout!

For us, we are on that image TOU tariff, and over Feb, we could charge a battery between 0% - 25% (weather depending) from solar and the remaining overnight at very low prices. In summer this changes to charging the battery between 30 - 55% (weather depending) and again charging the remaining overnight during off-peak. The projected annual electricity cost saving for us (with an EV) compared to without the solar+powerwall is +£900, with an average monthly bill of £20.

For us the quote for a Sonen 7.5kWh battery was much more expensive than a Tesla Powerall 2 13.5kWh. The Sonen also falls far short of Tesla’s discharge rate, meaning that when cooking/heating you may end up using grid power to cover the additional. The Tesla is also smaller and can be located outside. We are scheduled to have ours installed in late march by JoJu Solar.

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It’s limited to just a few Postcodes in the city of Lincoln.

Question on the Tesla, if you don’t mind.

Have you researched the noise level of this when running ? As loud as a home air-conditioner unit is one comment I’ve read. Do you plan to site it in a “far off” location so noise isn’t an issue ?


@victor So we don’t have it yet so can’t comment from first hand experience, will update this when we have it installed.

If that is comparing the Powerwall to the external air-conditioning unit, then no. From my rather obsessive research the unit when in operation is much quieter than that, the unit only makes any noise when the built in temperature control system needs to act. It’s possible that the older units were much louder, but the Powerwall 2 should be almost quite enough to have in a hallway (less ideal), certainly if you’ve got a large enough closet it, you would not hear it and for us, we are placing it outside and I very much doubt we will hear it at all.

In this video it’s described as about the sound of a fridge in operation, our fridge is rather quite and we have an open plan living room and have never been troubled by it. But ideally I would try avoid installing any device above 28db in operation, in TV/theater room if possible.

Thanks. The printed specs say it is <35db. However 34db is pretty loud (IMO). I used to build very quiet computers as a hobby and I’ve always believed that the quietist device is the one in a distant room (so NAS units in the attic etc). I think outside is definitely best although indoors in a remote garage would also be fine (subject to stringing power cables around).

Can I ask you about Solar Panels ? How many/large would I need to provide 3100kwh annually ? Where do I look for a Solar Panels 101 HowTo ? As you may guess I’m toying with installing Panels and a Battery.


PS. Good review on by Roddy Llewellyn (Red Dwarf). He says it just hums.

PPS The treehugger review features the company you mention - JoJu Solar.

Certainly not quiet, but I suppose it depends on the location you install said device and how loud other devices in that area are.

For those with a garage, it is often the best location. In terms of cables if the distance to the consumer unit is less than 10m that location should not be an issue.

Before You Begin

Sure. So the first two things when considering solar, is making sure you are building the largest system you can for your roof and wallet and a system with the fastest ROI. Sometimes a smaller but cheaper system will have a better ROI than a marginally larger system, but usually the larger the better.

Also now that the government FIT has been replaced with the Export Guarantee, you will now only earn money on the kWh you export back onto the grid and not your generation units as well. For the Export Guarantee, you will be paid on the exact number of kWh you export and not the old FIT assumption of 50% of your generation. This means two things:

  • You will need to find a supplier that supports the Export Guarantee and pays a competitive rate. Bulb has their: Export Payments @ 5.38p/kWh and Octopus have: Outgoing Octopus @ 5.5p/kWh
  • You MAY need to prioritse getting a SMETS2 (ideally) smart meter, and make sure this is fully operational with your supplier. As without it you won’t be able to track your export units.

Solar Array Size

Presently, no solar installer should honestly be installing panels bellow 300W, as 395W panels are classified as high efficiency panels and tend to cost a bit more than <340W. Bellow 300W should be reserved for very large residential installs with a massive roof. Most of us in the UK have not all that much roof space and High Efficiency panels will be worth every penny!

  • JA Solar - Good price vs performance
  • SunPower and LG Solar - Best High Effcieny pannels

So for 3100kWh annually you would roughly, based on our system, need about a 3.5kW PV array. See:

This will very largely depend on the following:

  • Roof geometry (South is best, but West and East work well too)
  • Pitch of your roof
  • Shading factor (Do you have large trees around your house)

So assuming you have a south or south-west roof with zero shading to hit 3100kWh annually you would need:

  • 12 - 300W panels OR
  • 9 - 395W panels

I would recommend SolarEdge for a roof with partial shading or large PV arrays (+12 panels) as it makes it easier to identify the exact panel that is causing a problem, if an issue arises. Otherwise save the money on a simpler string system.

Battery Storage

Lastly, if 3100kWh is your annual usage, bear in mind that a good portion of this will come after dark and during winter, November - February your solar will almost be off. This is where the home battery storage can come in.

For us, our ROI for Solar and Powerwall 2 is not that great +12 years, but if you can afford and have the roof space for a large +4.5kW PV array this will be dramatically shorter. As solar costs have dropped significantly in the last 10 years solar on it’s own often has a faster ROI than Solar plus a battery, due to batteries still being very expensive. With that said if you combine the Telsa Powerwall with the image Agile Tariff or Tesla Energy Plan, this could dramatically speed up your ROI.


YouTube will be your best friend, though a lot of these videos are based in the US, and don’t actually help us Brits out.

Our system was installed by E.ON, I would not personally recommend them, even though the job was done well. The reason for this is they did not at the time explain the true benefits of High Efficiency panels to us. They overall could have provided a better system for our limited roof space and marginally higher cost would have been worth while.

Installers will very much depend on your region, but get as many quotes from as many installers as possible and check their site for examples of previous installations and that they are insured and have MSC Accreditation, etc. You may find a wide variation in the cost and kW size that different companies will quote you.

JoJu Solar and The Little Green Energy Company are two of Tesla’s partnered installers for both Tesla Solar and Tesla Powerwall, but there are many others.


If you do decide to get Solar with/without a Battery, your installer will then need to submit a request to the DNO (Who is your DNO?) who will give permission to install equipment that can export back onto the grid.

This process usually takes 6 - 8 weeks.

The outcome will depend on your location, age of house and quality of the grid connection to your house. Most installs bellow I believe 3.6kW single phase should not be an issue. But if you have a large PV array or combine with a battery the grid connection to your house will need to be G99 certified.

I’m overwhelmed with the time you have taken to reply. Thanks so much. Just two comments - the installer I found on the Tesla site is not far from us luckily so I’ll start with him. The other seems to be a problem - we have a North/South house with limited Solar Panel real estate which, of course, is at the other end of the N>S axis to the Power entry point. The perimeter is >20m on each side. So that’s one to ask about.

Best of luck with your install. Maybe at the end of 2020 I’ll also have a definite plan . (Octopus is where I’m looking to move to soon, to go Agile and see whether we can shift our usage).

Lots for me to look at so thanks again.

No problem!

These are the questions that an installer will be much better at answering. They should technically be able to provide a no cost site survey to assess exactly what can be done, a desktop survey can also be done usually very quickly to asses if you can get solar on your roof at all.

Our house is 2 storeys, so due to the height we required a lot of scaffolding, but this was not a problem for the cable routing, a +10m cable goes from our utility cupboard, up the property’s exterior facade and into the attic where our Inverted is located.

Just want to add that OVO are not offering free Powerwalls. This is only for the Lincoln area and they are Sonnen storage units.

Hey @Pantalaimon, @victor, @redw756389, @mattcartlidge :wave:,

I thought you guys might be interested in Kit’s recent post on batteries? I’m sure he’d love to hear your thoughts. :thought_balloon:

I’m looking at getting solar panels and a battery system. We use a lot of electricity for a small household (assumed annual consumption 20,000 kWh). It comes down to cost, reliability, replacement cost.
I’ve been interested in supercapacitors as energy storage for a few years (e.g. and it seems that they might be close to being on par with lithium batteries, but longer lasting and more efficient. I’d be interested in your views.

Hi @philowen and Welcome to our Community :battery:

I would recommend having a look at this Community page: Product Input: Help us shine a light on batteries

In this thread, there is a link where you can sign up to get the latest updates about the lastest battery products and services from Bulb.

Did JoJu install your solar panels - would you recommend?

Apologies for late reply, they did not install our solar PV, only our Tesla Powerwall and EV charger.

However, I would definitely recommend them for Solar, EV charging and home battery installation.

PM me for a referral code.