Frequently asked questions

Solar photovoltaics (PV) are materials that convert light directly into electricity, using no moving parts. It is made out of semiconducting materials, most usually silicon.

Solar PV electric panels do not require bright sunlight in order to operate, meaning that you can still generate electricity on cloudy days. The electricity produced is either consumed directly by appliances in the building or, if more power than required is generated, it is exported to the grid. At night, or when the system is not producing enough energy, power is supplied by the grid in the normal way.

Solar PV works from daylight and not direct sunlight, but normally more power is produced on a sunny day than on an overcast or cloudy one. PV panels do not produce energy in the dark and so during the night electricity is drawn from the grid in the normal way.

Any shade from trees, neighbouring buildings or overhead cables can have a huge impact on the performance of your PV system, so panels should be sited to avoid shading as much as possible.

However, there is a workaround where we can install power optimisers which increase the current on shaded panels to keep all the panels in the sun optimised for the string.

Generally, solar panels can be installed on any roof or free terrain with enough space to accommodate them, whilst trying to avoid shady places.

Solar can be installed on virtually all roof types – tiles roofs, slate roofs, flat roofs, trapezoidal metal roofs, standing seam roofs.

Solar panels can of course also be installed on the ground as well, from back-garden arrays to solar fields.

This depends on the amount of power you want to produce but normally installations of 4kWp (10 panels) will need approximate 6 x 4m square metres of roof space.

The size of a solar system is measured in kWp (kilowatt peak). It is the amount of power produced under standard laboratory test conditions, which broadly equate to bright sunshine. So a 2 kWp system will produce 2 kW of electrical power in bright sunshine. For standard modules of 16% efficiency, each kWp takes up about 6.25m2 of roofspace. More efficient modules are available, and because they convert light more efficiently, they take up less space. 1kWp of high efficiency 20% modules only take up 5m2 of roofspace.

This really depends on how much electricity you use within the home. An average house uses about 3500 kWh of electricity per year, but with energy efficient lighting and appliances it is possible to use half of this (1750 kWh per year.) A typical rooftop array in the UK is 4kWp in size, and produces about 3560 kWh per year.

So yes, it is possible to produce more than you use on an annual basis. The caveat here is that generation does not perfectly coincide with demand in the house – PV produces less electricity in winter, and of course none at all at night-time.

We should also point out, that the above is electricity for lights and appliances only - it does not include demand for hot water, ASHP's. Increasingly we are seeing customers wishing to use solar to meet demand from electric vehicles as well, which is an additional electrical load.

This varies depending on manufacturer but most come with manufacturers 25 linear and product warranty and have an expected life well in excess of 25 years.

The total installed cost of a system will depend on the size of the system and ease of installation. It is not possible to give a precise figure without viewing your property. However, we do provide our package costs which will never be too far off the actual cost.

It is not possible to give an estimate of what your system will generate without visiting your property, as there are five main factors that will affect how much energy your system will generate:

• Total size of the PV array (number of panels)

• Latitude of the location

• Direction the panels face

• Angle the panels are mounted

• Any shading

However, to give you an idea we would expect a typical unshaded 4kWh system installed in the North East with an unshaded south-facing roof sloping at an angle of 35° an 4 kWp PV system typically generates [3612] kWh per year.

We will model the output of your proposed system at the design stage and provide full projected details.

For systems less than 4kW peak power we will inform them once the installation is complete. For larger systems, application will be made on your behalf and permission will need to be gained from the distribution network operator (DNO).

This will depend on the size of the installation. Typically a residentail installation os solar PV will take 1 to 2 days to complete, depending on the complexity. This excludes the installation of scaffolding which will typically take 1 day to erect in advance and 1/2 a day to remove for a residential installation.

Yes, it is a good idea to speak to building control about your intentions and they will advise you if you need to take any further action.

However, we will notify them for the electrical part.

Most roofs are strong enough to support a PV installation without any reinforcement, but we will perform a site survey and make an assessment of this prior to installation.

If there are any modifications with the roof or signs of deterioration a structural engineer will have to make an assessment.

Pigeons nesting under your panels and fouling your property is one of the most frustrating issues faced by solar households. But it has easy solution, and we install it for FREE!

All our package installations come with free bird protection kit.

Most panels are szelf-cleaning and dust and dirt usually washes off when it rains if the panels are installed at an angle of at least 15 degrees. In extreme cases, dirt may cause a power reduction of about 10%. We suggest an annual clean using a pressure hose.

No, solar PV systems do not need batteries as excess electricity is fed back in to the grid.

However, they will significatly improve your efficiency by storing that excess energy and using it during more expensive peak tariffs.

While solar panels might produce less energy during the winter due to fewer hours of sunlight and a lower sun angle, they can still be effective. Cold temperatures can actually enhance their performance.

Battery storage allows you to store excess electricity generated from your home's solar panels or charge them from your main supply. You can charge your battery overnight and use the stored energy during peak hours when tariffs are high or when solar panels aren't producing energy. Allowing you to not waste any energy – store it and save!

Homeowners are opting for battery storage for multiple reasons.

• Self-sufficiency. Generally, people want to be more self-sufficient and to run their homes off the electricity they have produced themselves.

• Getting the cheapest electricity. A home battery can allow you to store cheap night-time electricity for use at other times. It means you always access the cheapest possible electricity, whether from solar or the grid.

• To run their car on sunshine. Even if you are out during the day, you can still use solar electricity to run your car. Store your generated electricity in a home battery, and then discharge this into your vehicle when you return home. This will give you significant savings over the year.

• Make money as a grid trader. by charging overnight and selling back at peak times. Some bayttery owners are making a profit on their electricity.

• Some areas are prone to power cuts. Some models of batteries allow you to use your stored electricity in the event of a power cut.

The cost of a home battery system will vary, depending on the make and model of system that you choose. You will also need to consider installation costs, which can also vary, depending on the complexity of the work that needs to be done.

For example, some of our customers choose to upgrade their solar array and/or install an EV charging point at the same time as we install the home battery system, which can mean a big saving on having these three things done separately.

Some installations may require a separate inverter to be fitted and some will be able to use the same inverter as your solar panels. We can offer expert guidance as to the best system for your existing setup and home.

The cost of a home battery system will depend not only on the brand of product, but also the size/capacity of the battery itself. Currently, the Tesla Powerwall offers great value per kWh of storage, but if you are a smaller or less busy household then you may be better off with a smaller and cheaper system with less energy storage capacity.

Whilst most people use home battery energy storage systems to maximise the solar energy generated by their PV system, some systems can be used in households without solar arrays. Not all products have this capability, but some, such as the Tesla Powerwall, can be set up for this purpose.

Instead of being charged by solar energy, these battery systems can be charged with 'cheap' off-peak electricity from the grid (for homes on tariffs offering cheaper off-peak energy, usually overnight). This stored energy is then used during peak times, reducing the need to draw 'peak-rate' energy from the grid. Consequently, this can lead to savings on electricity bills.

If you are currently receiving feed-in tariff (FiT) payments for the electricity you generate with your solar PV, they will not be affected if you install a battery energy storage system.

The FiT scheme was discontinued for new home solar PV systems installed on or after 1 April 2019, but existing qualifying households won't lose any of these payments for the duration of their contract.

This is acheived by installing your new battery with an AC coupled inverter meaning the exiting install is not touched.

The size of battery energy storage system you need will depend on your home's size and energy requirements. The average household uses between 8-10 kWh of electricity per day. Battery storage range from 2.5-5 kWh in capacity for small systems up to 13-15 kWh for larger systems.

We typically size a system using a two-step approach:

1. Economically, the ideal battery size covers your evening and night-time usage (with a little extra). Your electricity demand should empty the battery by morning, maximising space to capture the next day's sunshine.

2. We then compare this to your solar PV system size. There's no point having a large battery if your generation is small, as you'd never fill it.

In practice, some home battery systems are sized to the home's demand, while others are sized to the solar PV system's output. Getting this right is complex, which is why our expert engineers help you find the right system for your home.

Remember that home storage batteries might not receive enough energy to charge every day, depending on weather and your home's solar electricity generation and usage.

With a correctly-sized battery system for your UK home, you should ideally have enough energy to meet your evening and overnight needs for most of the year. However, you're likely to need grid electricity in the winter months.

When battery storage allows you to utilize your solar PV system for charging, determining the duration they can power your home involves considering the battery's capacity and charge level.

For instance, top-tier options like the Tesla Powerwall could potentially sustain your household for over 24 hours on a full charge. However, factors such as partial charging or smaller capacities can impact the duration of power supply.

In terms of longevity, the lifespan of a home battery system varies based on the model and usage. Despite undergoing numerous charge-discharge cycles, these batteries generally experience minimal capacity loss over time.

Manufacturers typically provide warranties, such as Tesla's 10-year warranty ensuring 80% original capacity, suggesting that these systems can often outlast their guarantees.

Our expertise can guide you in selecting the ideal home battery system and ensure clear comprehension of all warranty details for a seamless installation experience.

All of the major manufacturers of these systems offer a warranty, usually around 10 years, although there are some restrictions and caveats on usage for some products. If you choose Greenbase Solutions to install your home battery system, we can match the best type of system, with a warranty that you’re comfortable with, to your home.

For many homeowners, installing the battery system in the garage proves to be a popular choice, as it provides some level of protection from various weather conditions.

Most battery storage manufacturers now offer the flexibility of indoor or outdoor installation, catering to the UK's temperate climate that generally avoids temperature extremes. However, for outdoor installations, you would need to ensure that a battery system installed outside is kept clear of debris like leaves and an accumulation of snow, and that it is safe from potential flooding. Also direct sunlight may be an issue.

Determining the savings of battery storage is very difficult, as it depends on your consumption habits and energy generation capacity. Through our analysis, we discovered that battery storage can enhance the cost-effectiveness of a solar PV system in specific scenarios.

When paired with a sizable solar PV array, the battery can be charged predominantly by solar energy, refining the economic viability of the home energy storage system.

Even in circumstances where solar energy isn't abundant, the ability to supplement with affordable overnight grid electricity significantly boosts the return on investment.