Read about how and why we choose Cotswold Energy.

Particularly in Lower Mill Estate, there are a significant number of people with additional homes elsewhere in the UK. You can request a quote for another house by filling in the application form a second time with the address of the additional house.

The supplier will be able to discuss a quote with you. However, they are based in Gloucestershire, so may not be cost-effective for installations that are too far away due to travel and accommodation costs.

In theory, almost any roof can have solar installed, although the cost and efficiency will depend on how complex it is to install and the direction the roof faces (south will generate the most electricity). Therefore your specific home will affect how quickly you get a Return on Investment (ROI).

There are types of solar panels that might suit metal roofs better and you may need additional supporting structures if you have a flat roof. Even a sundeck roof (that you can sit on) could have solar installed, but this may either reduce the available seating space or need to be an overhead canopy that would shade the roof and may need planning permissio

Yes, there are three limits:

First, there is an automatic approval soft limit of 3.68kW, which is between 10 and 13 panels. Beyond this “soft limit”, the installer will need to get permission from Scottish and Southern Electric, who will need to check there is sufficient capacity to handle this. The process will add a bit of time and possibly money.

Second, there is a limit to how much electricity your house’s grid connection can handle, nearly all homes have what is called “single-phase power”. It’s unlikely a rooftop solar installation would exceed this limit.

Third, it is possible to have three-phase power installed, which will increase the maximum by 3x. This is quite expensive, at least £1,000 and potentially much more. This is likely only relevant if you wanted a large ground-mounted solar installation.

Generally not, as it fits under “permitted developments”, subject to meeting specific conditions. However, there are exceptions that could require planning permission, for example, if your house is a listed building or in a conservation area or you are installing on a flat roof where the panels will be higher than the roofline. For more information see: Planning Permission: Solar equipment mounted on a house or a block of flats or on a building within the curtilage – Solar panels – Planning Portal

Note: For Lower Mill Estate residents we will need to apply to the landlord for permission. We have been discussing this with LME and they will permit a bulk application for all the homes as one to save time and cost.

Yes, absolutely!

Note that you will need to pay VAT as the VAT exemption only applies when installed at the same time as solar.

Depending on your current Inverter the battery may be able to connect to this, or a new inverter maybe required. The supply will advise after surveying.

Yes, absolutely!

If your home isn’t suitable for solar panels you can still install a battery with an inverter and optionally an EV charger.

While you won’t benefit from solar generation the battery can still reduce your electricity costs and carbon footprint. The savings come from charging the battery with cheaper, lower CO2, off-peak electricity and using the stored power during the day/evening

Note that you will need to pay VAT as the VAT exemption only applies when installed at the same time as solar.

No, since we focusing on finding a solar + battery supplier, who can also include EV charging as part of a solution, the supplier does not do pure EV charging solutions

The supplier may propose a configuration for your home where the maximum output of the panels is a little higher than the capacity of the inverter.

This is because the panel output is the peak, which is only achieved on very sunny days. Much of the time the output is less, for example, see the projected power generation by month below. This means only occasionally are you generating more power than your inverter can use. It may not make sense to install a larger inverter or multiple diverters for two reasons

1. Cost – the cost of the additional inverter capacity may yield little additional power generation savings over the year

2. DNO approval – if you go over the 3.8kW / 16A standard threshold, then special approval is required. This threshold is determined by the Inverter’s theoretical maximum output, not the panels. As with cost, it may not be worth going through this for little incremental gain

The supplier will propose appropriate-sized inverters(s) for your home. In most cases either one 3.8wK or 5kW inverter. However, if your home has a particularly large number of solar panels which exceeds the 5kW maximum of a single inverter you may get a proposal for more than one inverter, with the solar panels split between them

Yes, your EV charger will continue to work with solar/batteries.

However, the main benefit of installing an EV charger at the same time is that it will be part of the solar/battery system and can integrate intelligently together. For example, the system may choose to charge your car during the day if there is enough solar power, to reduce costs. A standalone EV charger will still work, but it won’t be controlled by the system and will simply continue to charge your car at the schedule set in either the charger or car.

Yes, this might be useful, particularly if you rent out your property.

The charger can be controlled and monitored via the GivEnergy App, for example, you could enable or disable it depending on a rental guest paying for the service. The App will also show the kWh usage of the EV charger, so you could charge based on the amount of usage – for example, check after a stay how much electricity was used by the charger and deduct this from the deposit. 

The EV charger can also be activated by an RFID card that you could make available to those that have paid for the service.

We are investigating options where rental guests could pay for usage directly online. 

Yes, as long as the loft is large enough and there is suitable access. The batteries in particular are large and heavy, so loft installation may be more complex requiring hoisting of the equipment into the loft.

In addition batteries, in particular, should not be exposed to high temperatures (50C+) and ideally much less for maximum battery life. Therefore loft insulation may require additional ventilation, such as a temperature-sensitive fan.

You will need to sign up for a Feed in Tariff (FiT). This will pay you for any excess electricity you generate. The rate you sell at will be less than the peak time usage rate, so its better to use electricity if you can and only sell what is left over

Contact your electricity supplier, all are required to offer a FiT under the  Smart Export Guarantee (SEG) | Ofgem.

The current SEG FiT price is 5.24p per kWh.

If your supplier is Octopus Energy they offer both the standard SEG FiT pricing or Octopus Outgoing which currently pays either a flat 15p per kWh or a variable rate based on wholesale prices. However, you can only be on a standard Octopus supply tariff to use Octopus Outgoing, you can’t use their Smart tariffs like Octopus Go or Intelligent Octopus. You will need to do some calculations based on your projected generation and usage to see which is the most cost-effective.

Not if you just take the system and are not selling electricity.

However, if you wish to sell excess electricity with FiT then you will need a Smart Meter, which your electricity supplier should fit for free. There are many people in the community with Smart Meters so we know they work in our neighbourhood, despite the poor mobile coverage.

Almost certainly not, but your bill should be reduced.
When the solar panels are generating electricity, the power will be used first by any device that is switched on in your house. The power you don’t use can either be stored in the battery (or hot water) to be used later or sold to your electricity supplier – using what is called the Feed in Tariff.
Over the course of the year, the average house with a “typical” number of solar panels installed will use more electricity than the solar generates. However as you switch devices on/off and as the weather changes, you may be importing from the grid one minute and exporting the next. At some times of the day, you may use more than you generate (so you’ll pay to import the balance from the grid via your electricity bill). At other times your solar may generate more than you are using at that point in time (a surplus).

Sadly there aren’t any government grants for solar or batteries, although they have zero VAT rated these when installed together.

There is a grant for landlords that rent out properties towards the purchase of EV chargers. If you rent out your property you may be able to apply. See here for details.

If you rent your home with AirBnB they are offering some grants. See here for details.

It’s worth checking if your mortgage provider offers anything, for example, Barclay’s offers grants. See here for details.

Generally not as the UK gets a lot of rain which washes the panels. However, if the panels get visibly dirty and this doesn’t wash away in the rain you may need to get the panels cleaned. It’s recommended to use a company/person experienced in cleaning solar panels.

For safety turn off the panels (this will be explained in the handover instructions) and avoid cleaning on a hot sunny day as the panels can get very hot and it’s best not to wash hot panels.

No routine maintenance is required.

The only “maintenance” required would be in the event of a problem, where the supplier would investigate and rectify. During the two-year installation warranty, this would be free. After the installation warranty period, the supplier would charge for labour. Faulty equipment would be replaced by the manufacturer if still under the product warranty. Outside of product warranty, the supplier would charge for repair or replacement.

When it’s snowing the weather is cloudy so you won’t be generating much.

Snow may settle on the panels and this will block the light and stop them from working. However, they are slopped and quite slippery so snow should clear relatively quickly.

If you decide to clear snow off the panels make sure they are turned off (see handover instructions) and be extremely careful not to damage them.

Yes, but we didn’t feel it was the right option for the initiative for three reasons:

1. Availablity: Current lead times are 12-18 months, which would delay the project too much

2. Pricing: With recent price increases the installed cost is over £10,000 for just the PowerWall and Inverter. Add to this the solar panels and there is a very large price premium

3. Options: The PowerWall only comes in one size, 13.5kWh. This would make the minimum size and therefore cost very large, compared to the 5kWh increments available with GivEnergy.

Note: The new GivEnergy All-In-One battery is similar to the Telsa Powerwall in terms of capacity and ability to provide whole-home backup.

None of the suppliers who quoted offered Solar Edge.

No, we are simply facilitating a good deal by using the power of a bulk purchase by local homeowners. We won’t be buying or charging/selling anything for this part of the initiative.

Right now we are a Company Limited by Guarantee (ltd) it’s simply a community group.  We are setting up in two stages, first (now) we are set up as a standard Limited Company and second, we will convert to a Community Benefit Society, which takes a bit longer. Thames Head Energy is an organisation that is for the benefit of the community, no individual or 3rd party benefits from its profits, which will go to the community.

They are complementary.

Thames Head Energy’s objectives are to reduce energy costs and CO2 for the community, both rooftop solar, solar farms and renewable heating will do this.

If you install solar on your rooftop you will still benefit from our future solar farm(s) and whatever heat solution we recommend will use electricity, which will be cheaper if you have a solar rooftop as well as our solar farm(s).

The best way is to join our WhatsApp Group – we have two, join the one for your location.

Somerford Keynes, Shorncote & LME

Either click this link, or scan this QR code with your mobile phone camera.

Kemble & Ewen

Either click this link, or scan this QR code with your mobile phone camera.

We will also email out updates from time to time and you can reach us at info@thamesheadenergy.org

These are the home type at LME which have a flat roof that is accessible. We’ve looked at this for the astro-turd area which is approx 6x5m. Unfortunately, this is too small for solar, it would only accommodate 5-6 panels giving ~2.8kW and which would give small savings. Cost would be high as they would require planning permission (flat roof), special wind force surveys, special mounting system etc.

However, these homes could be suitable for a battery only option.

The following applies to pitched roof homes, which are primarily at LME.

Note: Flat Metal roofed homes are different, they would always use the standard panels on a roof mounting system.

After some investigation with Cotswold Energy there are two options for homes with pitched metal roofs:

1. Standard Solar Panels that use special metal roof brackets clamp onto the seams without piercing the roof. With the all-black panels this should be an unintrusive design
2. A solar film that glues directly to the metal roof. This gives a more visually integrated look. However, this option is a lot more expensive. Around £14,800 vs £7,000 for a standard 7KW system without battery. We have double checked this and looking at online prices for solar film it seems correct. Basically the film is very expensive. 

The datasheet for the solar film can be viewed here.

Homeowners wishing to use solar film should inform Cotswold Energy quote team.

Typically for solar installations under the 4kW limit, it is only necessary for the installer to notify the DNO (SSEN in our case) post-installation.

However, because of a relatively large number of installations in the area, SSEN has triggered a rule that requires the installer to submit applications in bulk for pre-approval.

VAT on batteries purchased standalone is 20%, they are only zero VAT rated when purchased at the same time as solar installation, which is zero VAT.

Cotswold Energy asked the VAT office for clarification on adding capacity post-installation but still related. to the initial installation to allow for adding capacity based on real-world usage data. Initially, they seemed to be approving that this would be zero VAT. However, when Cotswold Energy attempted to get them to confirm this in writing they were vague and non-committal.  Understandable Cotswold Energy can’t take the risk of selling post-installation battery capacity at zero VAT if the VAT office then forces them to pay VAT.

There is a lot of industry pressure on HMRC to zero-VAT rate batteries as a renewable power technology or at the very least confirm the zero VAT for expansion post-install.

Hopefully, this is resolved by HMRC by the time anyone might want to expand based on actual usage which would likely be based on a year of usage data. But of course, we can’t guarantee what HMRC will do.

To keep project management costs at a reasonable level Cotswold Energy is only able to model solar PV systems based on your existing electricity tariff and your existing pattern of usage.

As the tariffs available are constantly changing we advise you to assess the most appropriate tariff after installation. It may make sense to have gathered some actual usage data after the installation as you may change how you use electricity to maximise the use of solar. One of the benefits of being part of the community energy scheme is homeowners will be able to share experiences of how to maximise solar use and the best tariffs to use.

The recently launched Octopus Energy Flux tariff is specifically designed for our situation – a tariff for homes with solar and batteries. It offers excellent usage and export rates which take advantage of both solar generation and battery storage. This tariff could significantly improve the payback period and % rate of return compared to the standard model against your existing tariff. As above it is not possible for Cotswold Energy to do “what if” modelling based on this tariff. There is a useful App called Octopus Compare for Octopus customers that allows you to compare your bill on any combination of different tariffs based on your actual usage to choose the best one.

Following the survey, some homes are not suitable for solar. This is normally because there isn’t sufficient unobstructed roof space to fit enough solar panels to make a viable system. Roof orientation and shading from dormer windows, chimneys and trees also affects.

We are working with Cotswold Energy to be able to quote a battery-only option. They are awaiting a software update to their modelling software to project the cost and CO2 savings ROI.

Very rough numbers are the 9.5kWh battery could save you around £1,000 per year by using cheap, l0w CO2, off-peak electricity from an overnight charge during part of the day, cutting your expensive, higher CO2, peak rate usage. This would give a similar ROI as solar only system.

We will let people know when this option is available to quote and for customers who have already requested this Cotswold Enerrgy will send a quote and estimated ROI.

We advise waiting for the new GivEnergy charger as this will be more integrated with the rest of the GivEnergy-based system and provide “solar diversion” – excess solar is sent to the car charger during the day. Cotswold Energy will in be contact when the product becomes available and we will be announced on the WhasApp group

The manufacturer is still stating that will be in the second quarter of this year.  All EV chargers will be quoted and invoiced separately as they are not currently classed as ESMs by HMRC and are therefore subject to VAT.

Anyone who does not wish to wait will be quoted for a MyEnergi Zappi charger, which is highly regarded and also offers the solar diversion feature.

All chargers that require trenching work for cable runs from the property to the agreed charging point will be retrofitted. This is to minimise disruption around the site, and of course, the costs involved.

This primarily applies to homes at LME.

We had enquires from some homeowners at LME who didn’t have a parking space near there home if LME would let them install matting on the grass outside of their home so they could park by the house to charge.

We approach LME about this and they stated they are not supportive due the visual impact and would prefer to resolve the charging issue with the estate wide charger plans.

However, if a homeowner feels they have a plot where such parking could be done descretely they should contact LME direct to discuss.

This would be “ships in the night” to Cotswold Energy, they will install the EV charger where they are instructed to.

A number of homes, particularly at LME, don’t have the interior space to install the Inverter and Battery and therefore will require external installation. 

Cotswold Energy are working with a contractor for a design to enclose externally mounted equipment to keep it neat. We are awaiting the design to review. 

Solar does not need CDC planning permission except where:

• The house is in a conservation 
• The house is. listed building
• The house has a flat roof (solar will be above the roof line)

At LME permission is required by the landlord. We have agreement to do this in bulk. We are waiting for Cotswold Energy’s details on the enclose to final the permissions with LME.

Smart Meters use a special version of the mobile network to communicate. Unfortunately with poor mobile coverage in this area, some homeowners are reporting issues with Smart Meter installations. A Smart Meter isn’t required for solar, but it is if you wish to sell excess electricity. 

After some investigation and advice from a homeowner with industry experience, it seems there is a solution – basically a separate antenna the engineer can install up high, well away from the meter box where a better location combined with a bigger antenna should solve the issue. However, you may need to push your electricity company to do this, or possibly switch. Here is some information to help you push.

EDF have a guide for their installers, this very clearly layout the options that are described below. If you get the runnout tell you elecicity company to read the guide and get on with providing the right solution – they are probably trying to avoid the cost of the better solution.

1637_smets_2_install_and_leave_-_sku_2_installation_-_final_v1.1.pdf (edfenergy.com)

Here the four options in order from best to worst in handling signal.

Best

The best signal strength is where the engineer fits the Smart Meter with SKU2 optional comms unit with external antenna connector:

And combines this with the Antenna T2 – this has a long lead and can be fitted high in the house, in this photo in the loft:

More information here: There is hope for anybody trying to get a smart meter in a poor signal area | Speak EV – Electric Car Forums

Second Best

This is the same as above but with the T1 antenna, this has a short cable, so the antenna has to be in or near the meter box, which is less good for a signal.

Third Best

This is the option we’ve seen tried and failing at some homes. This uses the SKU1 comms unit, sometimes called a signal booster. Because this has no external antenna it doesn’t improve the signal that much.

Worst

Standard Smart Meter only. This has no booster, no external antenna and therefore the worst at handling poor signal.