In the UK the  Energy Saving Trust (EST)  have been doing a  long-running trial of 88 solar hot water systems, also known as solar thermal systems.

Solar thermal panels use the sun to heat water in homes, rather than generate power, as solar photovoltaic (PV) panels do.

The UK trial shows that things like good  installation,  insulation of the pipes and water tank are all key in improving the performance of a solar hot water system, so you can save the most on your heating bills.

The trials found that solar hot water systems on average – normally provide 39 % of  all the hot water a home needs.  Which is probably somewhere between  £60-£90 savings on energy bills per year.

But  if the system is well installed and used correctly , it could provide 60% of the home’s hot water needs.  A badly installed and run solar system could provide as little as 9%.

Users need to make sure they are  insulating their tank and pipes, getting the right system size and setting up pumps and timers correctly.

Solar payback time

With solar thermal systems in the UK costing about £3,000-£5,000,  payback time is still a big issue -  issue and might explain why there aren’t many systems installed in the UK.

The new BBC Dragons Den had the investors all queuing up to give money to a company called PloughCroft Solar that installs solar panels to generate electricity.

In the UK – the Government pays householders to feed electricity generated into the national grid.The rate is 43.3p per unit of electricity  – this  Feed-in Tariff is guaranteed until 2035.
A 2kW system, on average, should  result in UK householders being paid  £900 annually as well as saving £140 on their own electicity bill.
WIth typical installation costs of around £11000  – and with electricity prices rising every year – householders could make a profit over 25 years of at least £10000

Solar PV or Photovoltaic cells generate  electricity from  a series of crystalline silicon cells, grouped into a framed panel and encased in toughened glass. The action of light on these cells is to create a direct current, which is then converted to alternating current which can be used in the home or can be  fed into the National Grid.

As with “normal” solar panels  – they are usually fitted onto the existing roof, although there are some which fit flush, and replace the existing tiles or slates.

Here in Ireland – we are not so lucky. ESB Electric Ireland currently offers a “Micro-generation”  payment of just of 9 cents per kWh to residential customers. The UK payments are more than 5 times the Irish levels.

If you are interested – here are the contact details for the ESB :

ESB Electric Ireland Micro-generation Scheme:

General Enquiries 1850 372 372

Registration for payment contact:

Dave Byrne 087 647 1791

Postal address:

Micro-generation Scheme

ESB Electric Ireland

FREEPOST F9

27 Lower Fitzwilliam Street

Dublin 2

email:  microgen@esbelectricireland.ie

Solar energy is the ultimate renwable energy source.There are three methods used in Ireland to get the benifts of the suns heat and energy.

Passive solar energy homes is a way in which homes are bulit to maximise solar gains in the home by avoidin g heat loss thorugh the buling and ensuring a good level of comfort by ventalitaion.

Another method used in Ireland is Active solar heatin.this is the way solar collectors (solar panels) are used to transform sunlight into heat.

The final method used is solar photovolatic systems.This is the use of semiconductor materials to convert solar energy into electricity.This si used in outdoor lamps or watches.It is now used in Ireland as a application when grid connection is too expensive

Your home’s windows, walls, and floors can be designed to collect, store, and distribute solar energy in the form of heat in the winter and  reject solar heat in the summer. This is called passive solar design or climatic design. Unlike active solar heating systems, passive solar design doesn’t involve the use of mechanical and electrical devices, such as pumps, fans, or electrical controls to move the solar heat.

Passive solar homes range from those heated almost entirely by the sun to those with south-facing windows that provide some fraction of the heating load. The difference between a passive solar home and a conventional home is design. The key is designing a passive solar home to best take advantage of your local climate.

You can apply passive solar design techniques most easily when designing a new home. However, existing buildings can be adapted or “retrofitted” to passively collect and store solar heat.

The Passive House concept represents today’s highest energy standard with the promise of slashing the heating energy consumption of buildings by an amazing 90%

A Passive House is a very well-insulated, virtually air-tight building that is primarily heated by passive solar gain and by internal gains from people, electrical equipment, etc. Energy losses are minimized. Any remaining heat demand is provided by an extremely small source. Avoidance of heat gain through shading and window orientation also helps to limit any cooling load, which is similarly minimized. An energy recovery ventilator provides a constant, balanced fresh air supply.

Direct gain is the simplest passive solar home design technique. Sunlight enters the house through the aperture (collector)—usually south-facing windows with a glazing material made of transparent or translucent glass. The sunlight then strikes masonry floors and/or walls, which absorb and store the solar heat. The surfaces of these masonry floors and walls are typically a dark colour because dark colours usually absorb more heat than light colors. At night, as the room cools, the heat stored in the thermal mass convects and radiates into the room.

An indirect-gain passive solar home has its thermal storage between the south-facing windows and the living spaces.

The simplest and most reliable sunspace design is to install vertical windows with no overhead glazing. Sunspaces may experience high heat gain and high heat loss through their abundance of glazing. The temperature variations caused by the heat losses and gains can be moderated by thermal mass and low-emissivity windows

Solar water heating

An average household can save about 50% of the annual cost of hot water using solar panel.

There are two main types of solar water heating panels - flat plate and evacuated tubes (referring to the way in which water interacts with the panel). Evacuated tubes are more efficient than flat plate versions, so are often smaller but generate equal amounts of hot water.

Choosing a solar water heating system

When choosing a solar water heating system, you’ll need to consider a number of factors including your average hot water usage, the area of south facing roof, the existing water heating system and your budget.

You’ll need roughly one square meter of collector area per person in the household. Each metre of panel area will need between 30 and 60 litres of water tank volume.

If you use a less efficient collector (like flat plate solar water heating panels), you’ll need to cover a larger area than if you use a more efficient collector (like evacuated tubes). You’ll also need to select system components (like a hot water cylinder, controls and pipe work) and choose the location for your panels considering shade, pipe runs, roof pitch and future access.

Solar water heating can provide about a third of your hot water needs
Pros

* Solar water heating can provide you with about a third of your hot water needs and about £40 a year off your hot water bills, depending on the fuel replaced.
* Solar energy is free, plentiful and clean.

Cons

* Provides hot water but not electricity.
* An unshaded, south-facing location is necessary to install solar panels.
* Initial costs are higher than conventional electric and gas-heater systems.
* Solar panels can be heavy, so your roof must be strong enough to take their weight, especially if the panel is to be installed on top of existing tiles.
* Solar panels are expensive compared to the amount of electricity they’ll produce in their lifetime.

Photovoltaic (PV) solar panels

PV solar panels generate electricity from the sun’s energy rather than just heating your water. You’re more likely to see these on offices or large developments than on homes.

You can use PV systems for a building with a roof or wall that faces within 90 degrees of south, as long as no other buildings or large trees overshadow it. Less energy will be generated if the roof surface is in shadow for parts of the day.

The are three basic types PV panels: monocrystalline, polycrystalline (or multicrystalline) and amorphous. All are made from silicon, but differ in the way the silicon is cut and treated to create collar cells.

To install a system you need to decide how much electricity you want to generate. After submitting details of your property, a PV installer should help you to conduct a site survey and discuss your options with you.
Pros

* Only daylight is needed to create energy – not sunshine.
* Can cut average household electricity bill by about 30%.
* Solar energy is free, plentiful and clean.

Cons

* A large roof area is needed to generate lots of energy.
* Significantly more expensive to buy and install than solar water systems.
* Solar panels are expensive compared to the amount of electricity they’ll produce in their lifetime.
* The efficiency of solar panels depends on the number of solar light hours and climate.
* Initial costs are higher than conventional electric and gas-heater systems.
* An unshaded, south-facing location is needed for installation.
* Solar panels can be heavy, so your roof must be strong enough to take their weight, especially if the panel is to be installed on top of existing tiles.

PTSB have launched a Green Mortgage – basically any PTSB Irish mortgage applicant can ask for the Green Mortgage – and get  the following

1. 10% off a Botanic Greenhouse at www.botanicgreenhouses.ie

2. €1,000 discount off a Shomera at www.Shomera.ie

3. 15% off a new bicycle at www.cycleways.com

4. Free electricity meter (worth €42) when you spend €150 at www.ecoshop.ie

5. 10% off all solar powered needs at www.solartechnology.ie

6. 10% discount and free delivery of all water collectors at www.ecoshop.ie

7. A tree planted in the mortgage customer’s name by the Tree Council of Ireland.

8. A chance to win one of 50 home energy surveys from National Energy Assessors .

Once customers have completed the tie breaker question on the Green Mortgage Form they will be in with a chance to win an Energy Assessment.

National Energy Assessors will conduct an assessment of the winning customers’ homes and advise them of any energy saving methods they could adopt into their home.