Renewable Energy: A Comprehensive Guide to Solar (Part 2)

This is the second part to the first post in our new Renewable Energy series, where we will give the ins and outs of renewable energy that is able to be used throughout residential and commercial spaces.


What is it?

There are three types of solar: PV, Thermal and Hybrid.

The PV stands for photovoltaics. These systems convert sunlight into electricity – that doesn’t mean that it needs to be a hot summers day, though, the photovoltaic cells can still generate electricity on your average British day.

Thermal does as the name states, it uses the sun’s energy to generate thermal energy, which can be used to heat water or other fluids, but can also be used to power solar cooling systems.

Hybrid is the newest of the three, which is a combination of the previous two. These systems bring together advantages of both PV and Thermal, boasting the convenience of a grid connected system, with the battery backup.

Part 2, will focus on Solar Thermal. Keep posted for the following parts of our Solar instalment to this series, to read our guide to Hybrid Solar Energy.

How does it work?

Photo credit: renewableenergyhub.co.uk

A solar thermal system uses the sun’s energy and converts it into heat. The energy received from the sun is transferred into heating systems in the form of hot water or heating. The main source of where the heat will generate from is from solar panels, usually roof-mounted. These panels are connected to either a boiler or immersion heater.

Now, this is the complicated part; the solar collector will use the sun’s rays to heat a transfer fluid which is usually a mixture of water and glycol, which stops the water from freezing. The heated water from the collectors is pumped to a heat exchange which would be inside the water tank in your home. The heat from the exchanger will then heat the water inside the tank. After the liquid releases its heat, the water will flow back to the collections for reheating. A controller will ensure that the fluid will circulate to the collector when there is insufficient heat available.

How much carbon goes into producing it?

A solar thermal system goes through five main phases in its life cycle: raw material extraction; materials possessing; final product manufacture; transport and installation; and recycling and disposal.

The average process of manufacturing a solar thermal system will produce roughly 1000kg of CO2. The energy payback period on the average flat plate system is roughly 1.5 years.

How is it beneficial?

  • No fuel cost
  • 24/7 power
  • No pollution
  • Existing industrial base
  • Good ROI (return on investment)
  • Very efficient

How efficient is it?

The typical output of a domestic solar thermal installation is between 1000kWh and 2500kWh. The average householder can expect to receive around £200-400 per years in payments, on top of a reduction in energy bills. To be clear, though, solar thermal energy will not be able to cover your entire hot water/heating consumption – the figure is usually between 40-60 percent.

How much does it cost?

For a solar energy system, you can expect to pay between £3,000-5,000; this price is dependent on the type and quality of the system. A typical well-insulated twin coil cylinder system will be priced at around £4,500.


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