Domestic Renewable Energy

There is a range of renewable energy technologies that are now available for domestic use which can help you meet your energy requirements. These make use of the sun, wind or renewable fuels to generate heat and electricity. But how reliable are these technologies? How much energy can they actually harness? What are the costs and most importantly what is the payback time on your investment? This section provides an overview of the different technologies available and gives an impartial view on the benefits and costs of each.

A summary of the different renewable technologies available for domestic use is provided below, some generate electricity and some generate heat. Two icons are used to distinguish these, these are below:-

Generating
Electricity
Generating
Heat


Solar Photovoltaic’s (Without FITS)

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ROI
23 to 60-Years
NB Please note this article only relates to solar photovoltaic systems installed and operated without the Feed-in Tariff government incentive scheme and only looks at the true economies of the technology. Please refer to the energy saving trust for the latest on The FITs scheme as they do make a significant difference making solar PV economically viable.

The terms solar energy and solar power are often used to describe technologies which collect the energy of the sun and redistribute it for our use.   These terms are however a little ambiguous.  For example, solar energy effectively drives our whole planet, wind, wave and fossil fuels could ultimately be regarded as solar energy.   For the purposes of this site our only concern is for solar energy that can be collected directly by our dwelling and used to, for example, heat water or to drive our electric devices.  For this article only Solar Photovoltaic power generation is considered.  Please follow the link to take a look at Solar hot water.

 

Solar Hot Water

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ROI
32-Years

What is Solar hot Water?

 

The terms solar energy and solar power are often used to describe technologies which collect the energy of the sun and redistribute it for our use.  These terms are however a little ambiguous.  For example, solar energy effectively drives our whole planet, wind, wave and fossil fuels could ultimately be regarded as solar energy.   For the purposes of this site our only concern is for solar energy that can be collected directly by our dwelling and used to, for example, heat water or to drive our electric devices.  For this article on solar thermal hot water is considered.  Please follow the link to take a look at Solar Photovoltaic’s

 

Wind Power (Without FITS)

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ROI
13 to 52-Years
NB Please note this article only relates to wind systems installed and operated without the Feed-in Tariff government incentive scheme and only looks at the true economies of the technology. Please refer to the energy saving trust for the latest on The FITs scheme as they do make a significant difference making wind power economically viable.

This article is only concerned with wind turbines that can be sensibly added to a residential home.  Unlike other forms of renewable energy, wind power requires very little explanation.  Most of us will understand that the wind rotates a wind turbine generating electricity.    The question addressed here is how effective are they and are they worth the investment.  To work out how much energy you may generate you need to know how windy it is in your area, and there are several resource on the internet to do this, just do a Google search, or have a look the site by the  Department for Business, Enterprise & Regulatory Reform (BERR) it has a good resource for this, please follow the following  link.

 

Heat Pumps

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ROI
4 to 239 -Years




For those interested it operates in a similar way to a refrigerator working in reverse, it works on the principle of the vapour compression cycle within the pump.  There is a volatile fluid known as a refrigerant. The refrigerant in the evaporator is heated by the heat source this causes it to turn into a gas. The gas then passes through the compressor; the compressor increases its pressure and causes its temperature to rise. The hot gas then moves to the condenser where it is condensed back into a liquid and in doing so it releases heat into the house via a distribution system. The refrigerant is then allowed to expand back to a low pressure through the expansion valve and pass back to the evaporator where it repeats the cycle in a closed loop.

What are they?

There are three main types, these are:-

  • Ground Source Heat Pump (GSHP),
  • Water Source Heat Pump (WSHP), and
  • Air Source Heat Pump (ASHP)

They function by extracting heat from the ground the water or the air respectively and releasing that heat energy at a higher temperature within a building.   All heat pumps consume energy usually in the form of electricity to operate the pump that is required to transfer the heat.  They can supply all the heating you would require, and ground source systems are the most effective.  To compare the performance of heat pump the term coefficient of performance is used (COP) and it described the ratio of heat movement to energy input.  In the table below the Best Average COP is used.  This a seasonal average, since air source and water source vary in performance with the temperature of the environment.  For ground source the underground temperature is however remarkably constant all year.

It should also be noted that you will need a reasonable amount of land for an effective GSHP, unless you drill down, and for a water source heat pump a body of water is essential!