Why did you set up TCCEC?

I have been working with PV technology for nearly three decades - I installed my first PV system over twenty eight years ago. At the moment I'm advising as many people as I can about what to do when installing a PV system and I try to share my knowledge with them. It's a rapidly growing industry but people are being left to get their information from businesses that sell products. I believe it's important that people have the option of independent advice.

What is the difference between a solar panel and a PV panel?

'Solar panel' is a term that applies to both solar-thermal panels and solar-photovoltaic (PV) modules. A solar-thermal panel produces heat from solar energy and a PV module produces electricity from solar energy. Solar-thermal panels don't last as long as PV modules and all they do is produce a whole lot of hot water when you don't really need it. Gas will be phased out because of its high CO2 emissions and its cost - the house of the future will be heated by electricity.

How do PV modules work?

A PV module is made up of solar cells that are held together in a frame. PV cells generate electricity when photons come down from the sun and knock electrons from one side of the cell to the other. Each PV cell acts as a non-return valve, resulting in a build-up of electrons on one side of the cell. This creates a voltage difference between each side that causes (DC) electricity to flow when connected together by a conductor – i.e. a cable or electricity using appliance. 

How many PV modules do you need for a family home?

As of very recently, houses, regardless of location, may now install unlimited solar panels on their rooftops without any requirement for planning permission (subject to certain conditions). Exemptions also apply to rooftops of industrial buildings, business premises, community and educational buildings, places of worship, health buildings, libraries, certain public utility sites and farms. Certain restrictions continue to apply, including developments near certain aviation sites, protected structures and Architectural Conservation Areas. In my experience, a seven module unit is usually about the right size for a typical household.

How much will I save on electricity bills if I install PV modules?

This depends on how your household uses electricity and how you optimise your PV project to match that. People often don't realise how important it is to tailor and understand the system they use in order to minimise the amount of electricity they need to buy from the grid.

What is a diverter and do I need one?

A diverter is a device that diverts surplus electricity produced by a set of PV modules into something like a hot water tank. I usually recommend people get one because it allows them to turn off their gas boiler for most of the (increasingly long) non-heating season – April to September. A diverter will add roughly €700 to the cost of your PV project.

How do I know if my roof is suitable for PV modules?

Before you install PV modules, it is important to know if your roof is strong enough to withstand two types of load – the weight of the panels themselves and the additional wind loads that the panels will add to your roof. Wind speeds and directions are different all over the country so this is not a 'one-size-fits-all' assessment. It is essential that a competent/qualified person assess your roof to see if the existing roof structure is capable of carrying the loads of a PV module. This is non-trivial and it should be done.

Does the orientation of my roof matter?

There are software packages that will calculate the optimum slope and orientation for your location. There is roughly a 25% reduction in production if you rotate east or west from an optimum south-facing orientation. The loss is even greater for north-facing panels, but even they can contribute, depending on the ambition of your project. I always offer my clients a solid set of return-on-investment figures.

Is there a difference between all the different PV modules on the market?

At the moment, most PV modules on the market are very similar. They all operate at an efficiency rate of approximately 20%, which means they convert roughly 20% of the solar energy that lands on them into electricity. In general, it's a very competitive industry, very well regulated and protected by very mature standards.

Should I get a battery with my PV system?

In my view, no. Firstly, the production of batteries has a huge negative social and environmental impact on the planet. Also, after doing a significant amount of return-on-investment analyses, they don't stack up financially. It makes significantly more sense to sell your surplus power to the grid and essentially use the grid as your battery. Batteries are a significant financial outlay and they have a limited lifespan.

Can I use electricity generated by my PV modules to charge my electrical vehicle?

The short answer is yes, but in my experience it is often more economical to charge your EV with extremely low rate electricity overnight and use your PV generated electricity to reduce the amount of high rate daytime electricity that you consume.

What service do you offer?

When I take someone on as a client, the first thing I do is look at their household electricity bills and track their electricity usage to see how much they consume. Then I see if there are any initial changes that can be made to reduce that consumption and improve efficiency. After that, I create a 3D model of their buildings and grounds so we can discuss the optimum amount, placement and orientation of PV modules on their home or business. The next step is to come up with a tailored system that will give them the highest return-on-investment. I also provide three months of follow up support and advice so that they can make sure their project is up and running as they had planned.