Friday, 21 January 2011

Roof Mounted Solar Panels

Installing solar roof panels is one of the best investments for increasing the value of a property and reducing energy bills. A solar heating system could provide up to 70% of a homes annual hot water or electricity. The electricity produced by the solar panels can be used anywhere in the house. During the night the panels will not produce any electricity so all electricity will be bought from the grid as normal. During the day however, any unused electricity can be sold back to the national grid. Compare Solar Panel Prices and discover the benefits of isntallation.
Solar roof panels have improved considerably over the last few years making them even more efficient and an attractive green investment for the conscientious family.

Roof Mounted Solar Panels

Roof panels are known for providing solar hot water and it is the most common use of solar technology in the UK. Basically solar roof panels work by converting sunlight into electricity and this can be achieved even on a cloudy day. The panels take over the heating of the hot water in a home during daylight hours. This means there is no electricity or gas used to heat the water during the day. At night time the house reverts to using the conventional hot water boiler system.
The solar panels work by gathering heat during the day which is used to heat a fluid within the panels. This fluid then moves through the pipes to the heat exchanger which in turn is transferred to the water in the hot water cylinder.
Flat plate solar roof panels can also be installed inside the roof. These panels use a special low iron glass formula that increases absorption due to its reduced reflective property. This is achieved because the coated surface is not flat and is made up of thousands of tiny pyramids.

Do Solar Panels work in Cooler Climates

The simple answer is yes, solar roof panels are just as effective in cooler climes and work all the year round. Special solar panels have been developed and manufactured for use in temperate climates such as the UK and other northern European countries. These panels can be mounted on a southerly facing roof or alternatively on a east to west facing roof.

The Cost of Installing Solar Panels

The cost of course depends on the size of the home and the number of solar roof panels installed. For example a 1 -2 person system would average around £3,500 -£6,000 fitted. For a 4 person system the price would be around £7,000 - £9,000. Costs for larger systems with more roof panels and larger water tanks, range between £10,000 - £12,000. The largest domestic systems of 4kw would cost approximately £17,000 - £20,000. Although these costs seem high, solar roof panels are a long term investment and will easily pay for themselves in less than 10 years. Any excess electricity produced can also be sent back to the grid for resale to other homes and businesses. This arrangement will generate an extra 3p for each unit sold to the national grid. Additionally every unit of electricity produced will earn an extra 41.3p. Over a 25 year period this can add up to an additional £1000+ per annum, which is tax free.
British Gas is also now offering to rent the roof of any their customers and pay for the installation of the solar panels. The benefits for the customer include no installation costs and ongoing savings on the annual energy bill. These savings vary of course depending on the size of the property. For example, a roof with 20m2 area would equate to an annual saving of around £122; whereas a roof with 23m2 area would save around £152 on the annual energy bill

Tuesday, 3 August 2010

Understanding Biofuels

Biofuels, also known as agrofuels, are fuels produced from living organisms or from metabolic by-products like - plant biomass, vegetable oils, and treated municipal and industrial wastes. In order to be considered a biofuel, the fuel must contain over 80 percent renewable materials. Biofuels are considered neutral with respect to the emission of carbon dioxide. This is because the carbon dioxide given off by burning them is balanced by the carbon dioxide absorbed by the plants that are grown to produce them. The use of biofuels as an additive to petroleum-based fuels can also result in cleaner burning with less emission of carbon monoxide and particulates.

Biofuel types

Three most common biofuel types are: Bioethanol, Biodiesel and Biogas.

Bioethanol refers to ethanol liquid which is made from common crops including sugar cane and corn; and mainly wheat in the UK. It is the principle fuel used as a petrol substitute for road transport vehicles.

Biodiesel is the biofuel substitute for diesel. It is usually made from plant oils or animal fat through a series of chemical reactions. In the UK, it is derived from oilseed based crops – mainly oilseed rape (OSR). Because biodiesel essentially comes from plants and animals, the sources can be replenished through farming and recycling.

Biogas is the biofuel substitute for natural gas, and consists of methane. It is created from organic waste materials including animal waste and waste generated from municipal, commercial and industrial sources, through the process of anaerobic digestion. In the UK, biogas is mainly generated through animal waste. Examples of solid biofuels are - dried manure, charcoal and wood.

Biofuel burners

There are various types of biofuel burners. These include - basic log stoves and boilers, straw bale burners, wood chip boilers and wood pellet stoves and boilers. Wood-fuelled heating systems generally burn wood pellets, chips or logs to power central heating and hot water boilers or to provide warmth in a single room. A true biomass burner must be able to burn a wide variety of biomass. Since biomass grows in various shapes and sizes, it needs to be made into a standardised shape, size and density - essentially a pellet, in order to use all forms of biomass in one burner. The raw material could be wood, or it could equally be any type of straw or grass or practically any other type of biomass residue. Through processing the biomass into pellets it makes it much easier to design a biomass burner which can efficiently work with the fuel. Therefore, biomass pellet stoves and pellet boilers are the only true biomass burner.

Biofuel cars

The aim of biofuel cars is to be carbon-neutral and to reduce greenhouse gas emissions as opposed to conventional transport fuels. And the price of biofuel cars is also much lesser than the conventional car fuels. However, it is worth noting that biofuel cars are not really carbon-neutral; because it requires energy to grow the crops and convert them into fuel. The amount of fuel used during this production does have a large impact on the overall savings achieved by biofuels. Even so, biofuels still prove to be substantially more environmentally friendly than their alternatives. Another benefit of biofuels is that, they save the drivers' money. In the UK, the Government has introduced many incentives to drivers of ‘green cars’ based on emissions – with reduced taxation; dependent on how environmentally friendly the car is.
On the other hand, a lot of the first generation biofuels are not sustainable. It is necessary to create sustainable biofuel production that does not affect food production, and one that doesn’t cause environmental problems.

To conclude, whilst biofuel cars massively reduce carbon emissions and help you save cash too; they could negatively affect the habitat of many species and aren’t necessarily energy efficient at the production stage.