Here’s a list of commonly asked questions:

Q: What is PV?

A: Solar electric or photovoltaic technology uses the sun’s energy to make electricity. Learning from the word itself, the prefix “photo” means “produced by light,” and the suffix “voltaic” refers to “electricity produced by a chemical reaction.” PV technology produces electricity directly from the electrons freed by the interaction of sunlight with certain semiconductor materials, such as silicon, in the PV module. The electrons are collected to form a direct current (DC) of electricity. A complete PV system usually consists of one or more modules connected to an inverter that changes the PV’s DC electricity to alternating current (AC) electricity to power your electrical devices and to be compatible with the electric utility grid. Batteries are sometimes included in a system to provide back-up power in case of utility power outages.

Q: How do I know how what size system I will need?

A: There is no one right size for photovoltaic systems. Every site is different and the needs of system owners vary, too. System size depends on several factors, including how much electricity (in kilowatt-hours or kW-h) you consume, the orientation of the system, the tilt of the system, available space and funds. The first step to determining the size of the photovoltaic system you’ll need is to reduce consumption. Saving electricity is typically cheaper than generating it. Also, the smaller your overall consumption, the smaller and cheaper the system you’ll need. The second rule in photovoltaic system sizing is try to achieve the maximum FIT (feed –In Tariff) from the Government which is 14.38 pence up to 4 KW system. You should try to size your system equal to or less than your annual consumption. An easy rule of thumb is to take your annual consumption (in kWh) and divide that by 866 kWh/yr. (1kW of photovoltaic will generate about 866 kWh per year). This will give you an estimated system size. For example, the Smith's consume 6000 kWh per year, if we divide 6000 by 866 we get 6.92. This means the Smith's need about 6.92 kilowatts (kW) of photovoltaic to completely offset their annual consumption. Today in UK, payback is immediate, if you were to finance your solar system your payments would typically be less than the benefit that it replaces. A solar system will also add value to your property, reduce your monthly expenses and insulate you from higher and higher energy costs. If you were to pay cash for your system at today’s rates, you will typically recover all your investments within the next 5-7 years, but as rates go higher the time it will take to fully recoup your investment could easily be less than 5 years. Most people just get tired of sending £80 to £150 (or more) to their utility company every month so therefore putting the money into a hard asset seems like a better use of money. Finally, it seems right for our area and time. UK FIT may be decreasing substantially next year and UK Government refund may or may not be around forever and the utility rates have been rising at over 9% per year for the past decade with nothing but higher rate increases predicted for the future. In a nutshell the time to install solar feel like it is Right Now.

Q: How big is a typical system?

A: Solar PV systems range in size. A system composed of high efficiency cells will produce 1kW per hour for every 6.5 Sq. Mt. (This is the size of a typical 4 panels) Solar designers look for sites that provide an optimal southern orientation, good exposure to the sun, an adequate amount of structural support and space for solar panels to be placed. The best location for a PV system is on a south facing roof, but an east or west facing roof might also work. Flat roofs provide an environment for a variety of solar modules. Locating the PV system on the ground can work with either a fixed mount or a tracking mount system.

Q: Can PV systems produce power on cloudy days?

A: Yes. Although a PV system may receive 80-90% less sunlight on a cloudy day, the modules can still generate electricity.

Q: Do PV systems work well in the cold? A: Yes. In fact, photovoltaic systems generate more power when the temperature is lower. Because of the shorter hours of daylight and lower angles of the sun in winter, PV modules do generate less energy than in summer.

Q: Are PV Systems Safe?

A: Solar panels are a quiet, non-polluting source of energy. Like all large electrical devices, PV systems generate electricity and should be treated with care and maintained with the assistance of a solar professional.

Q: Is the “Tilt” of my solar array important?

A: The Earth is tiled on its axis at 23.5 degrees and regardless of where you live the difference between the sun’s peak angles in the sky from December to June is 46 degrees. Regions closest to the poles experience seasons when the sun never shines, and six months later, seasons when the sun never goes below the horizon. The optimum elevation angle for your solar system depends on your latitude. In general the optimum tilt angle is equal to you latitude, for this will ensure the maximum amount of sunlight over the course of a year. Even better would be to manually change the elevation of your solar collectors over the course of a year to follow the sun’s elevation in the sky. A typical roof angle is 18 to 32 degrees. As long as the collector angle (known as “tilt”) is at least 18degrees up from horizontal, additional tilt usually has little effect on total year-round performance. An exception would be areas with very sunny winters (as in most areas of Colorado) where a higher angle, facing the collector more directly into the winter sun, can make quite a difference.

Q: Will my system have batteries? What happens during a power cut?

A: With a grid connected solar PV system, the inverter will automatically disconnect itself from the utility grid when there is a power cut. This is to prevent back feeding the grid and putting engineers working to restore power in danger. Both of these systems will automatically hook back up to grid once power is restored. Q. Does PV add to the Resale Value of my home? A. PV “System Resale Value” for your home is about twenty (20) times the annual reduction in operating costs due to energy efficiency measures

Q: How much space will the solar electric system take up on my roof?

A: A good rule of thumb is to allow 6.5 Sq. Mt per every kilowatt of electricity the system produces. A 4 KW solar electric system for a typical home will require around 26 Sq. Mt.

Q: How long will my solar system last?

A: Most solar panels come with a 25 year power output guarantee and are expected to last at least twice that long. The power output guarantee on the solar panels is provided by the manufacturer of the panels and states that at the end of the 25th year, the solar panel will still produce a minimum of 80% of their original power output.

Q: Should I switch to a Smart meter once I get a system?

A: A time of use smart meter benefits customers who can export more than 50 % of what they produce .

Q: When is the best time to install solar?

A: The best time to install solar was last year and will always be last year. Solar electricity is getting more and more expensive as the FIT drop. Fortunately, electricity rates are increasing at a faster rate than the price of solar!

Q: How will the weather affect my solar electric system?

A: Solar electric systems are designed to withstand all weather conditions. Lightning, wind up to 80miles per hour, and extreme temperatures are all things your solar system can handle. However, thesec onditions will temporarily reduce its energy production.


A: Hopefully potential buyers will be pleased about the electricity savings and, if you paid for the system, the potential feed-in tariff profit will pass on to the new owner unless the benefit of FIT has been assigned to a company or electricity provider.

Q: Can I change my Electricity Supplier?

A: Yes. You’re not tied to any electricity provider, the feed-in tariff is a universal arrangement that Ofgem runs across all providers.

Q: Who pays the Feed-In Tariffs?

A: Electricity suppliers fund the payments.

Q: Will I be eligible to receive the tariff if I move into a home that already has an electricity generating technology?

A: FIT eligibility remains with the installation, even if the ownership of the home or generating technology changes. Therefore the technology must have been eligible before you move in, even if it is not registered yet.

Q: What happens if I move home?

A: Ownership of the technology is linked to the site and, therefore in the case where a building or homeownership changes, the ownership of the technology would also transfer to the new owner.

Q: I rent my property. If my landlord installs an electricity generating technology, who would receive the FITs?

A: It will be up to landlords and tenants of domestic or commercial property to come to an arrangement about the receipt of payments and on-site electricity use benefits.

Q: Will I need a special meter to be able to claim FITs?

A: Generation must be metered and FITs payments are made to generators on the basis of metered generation. Meters will need to be able to measure generation, usage and import. However, as an interim measure, DECC has announced that at the very small scale, the amount of exports for the payment of export tariffs can be deemed (estimated), subject to the following:

  • These arrangements will only apply until the finalising of specifications for smart meters;
  • These arrangements do not apply if export meters exist already, or are provided at the generator's expense

an I still claim the Feed-in Tariff?

A: Yes you will be eligible to receive a generation tariff at the tariff rate that is applicable for the type and capacity of the generating technology. You will also have to sign a declaration stating that all of the electricity generated on site will be used and not wasted.