With solar PV set to be mandatory for all new homes as soon as next year, there’s never been a better time to get familiar with solar panels. We sat down with Sam Ingham of Avon Renewables, who are experts in fitting and installing solar PV and battery storage for new and existing buildings. Sam answered some common questions which we hear from our clients and which we as energy assessors sometimes scratch our heads over.
What’s the best direction to face solar PV?
The ideal placement for solar PV panels is south-facing, as this orientation receives sunlight throughout the day until evening.
Is there still a benefit of fitting solar PV in other directions?
An east-to-west split roof can sometimes be equally beneficial. Mounting panels this way gives the best chance of capturing sunlight all day.
In some cases, combining south- and north-facing panels may also be worth considering, although north-facing panels alone rarely produce high yields.
What difference can having a battery fitted with your PV make to your bills/energy use?
Adding a battery to the right installation with the right usage profile can significantly reduce energy bills.
There are two main benefits:
- Capturing excess solar energy and storing it in the battery for use after sunset, effectively providing free electricity.
- Securing the best tariff to benefit from cheaper overnight rates. This allows the battery to be charged at night and discharged during cloudy or winter days.
In most cases, we recommend a battery alongside solar PV—particularly for households that are vacant during working hours. However, for a retired couple at home during the day, the extra cost of a battery may not be worthwhile as they already use solar power directly.
We know that solar panels and battery storage already have a big impact in SAP for the current building regulations. This is only set to increase with the Future Homes Standard next year.
How easy is it to fit pv to flats? Can the benefit be easily split amongst lots of homes?
Installing solar PV on flats is only possible when a single landlord owns the entire block and manages electricity distribution. In this case, the system can be designed to split the power between flats. If each flat has its own grid connection, sharing solar power is not possible.
Where the most unusual place you’ve ever fitted an array?
We recently completed a full solar PV and battery installation at a sailing club in Milford-on-Sea. This project posed unique challenges due to its coastal location, weather conditions, and site access. However, our team adapted well and delivered the project on schedule.
How do you as an installer estimate or calculate the best amount of solar panels for each dwelling, is it based off estimates of floor area and occupancy etc does the SAP calculation provide any help?
When assessing a property, we start with the known annual electricity usage (if available), dividing it by 365 to find the average daily usage. This helps determine the optimum solar PV and potential battery storage size.
We also use advanced modelling software, which factors in orientation, roof pitch, and shading, and provides estimated annual output. We then compare this with the property’s usage and present accurate feedback to the client.
What difference solar make to bills?
With enough solar panels, it’s perfectly possible to have no energy bills at all, though most people don’t go that far. On average, a typically sized and efficient solar PV array and battery installation can reduce a property’s electricity bill by at least 50%. However, results vary depending on site-specific conditions.
How long does it normally take to fit panels to a house?
A full installation for an average-sized property—including cabling, panels, inverter, battery installation, testing, and commissioning—typically takes around three days. Smaller systems can be completed more quickly.
Is it easier for a new build than an existing place?
Installation is much easier on new builds, as cable routes are accessible and we can make use of roofing and scaffolding already in place. This reduces costs significantly for the client.
The main challenge with new builds is the lack of measured energy usage. In these cases, we account for future needs such as EV charging or air-source heat pumps, often oversizing the array to future-proof the system, while undersizing the battery as it is easier to upgrade later.
What is integrated solar, is it harder to install?
Integrated solar (where panels sit flush with roof tiles) functions the same as standard panels but requires slightly different installation techniques. With the right products, systems, and procedures, our team handles these installations effectively.
Have you had any problems in conservation areas, or with listed buildings?
As a company, we have not encountered issues with conservation areas or listed buildings. However, planning permission is almost always required for these properties.
Do solar panels require planning permission?
Planning permission is also required in conservation areas, for listed buildings, and for large-scale projects (e.g., solar farms). It is the homeowner’s responsibility to confirm this with the local authority and seek professional advice where needed.
What’s the difference between kwh, kw and kwp?
Lets help with understanding common terms:
- kWh (kilowatt-hour): The unit of electricity consumption. For example, if a 1 kW appliance runs for an hour, it uses 1 kWh of electricity.
- kW (kilowatt): A measure of power, used to describe the size of equipment or a solar array.
- kWp (kilowatt-peak): The total output capacity of a solar array. For example, 10 panels rated at 500 W each would total 5 kWp.
What is the MCS certificate and why do I need one?
MCS certification is a crucial part of solar PV and battery installations. Benefits include:
- Assurance of a reputable contractor, as MCS requires strict compliance and annual reviews.
- Eligibility to apply for competitive energy tariffs (most providers require an MCS certificate).
- Potentially lower home insurance premiums.
- Essential documentation for smooth property sales, as buyers and solicitors will request proof of certification.
Thank you to Sam for your help!
