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Hi,

Ground source heat pumps can transfer heat from the ground into a building to provide space heating. This is possible because the earth a few metres below our feet keeps a constant temperature which in the UK is about 11-12C throughout the year, and during the summer months the ground because of its high thermal mass stores heat from the sun.

Ground heat pumps are a renewable source of energy as the heat comes originally from the sun. For every unit of electricity used to pump the heat, three or four units of heat are produced. Heat pumps comprise three main elements, firstly a loop or lengths of pipe buried in the ground in a horizontal trench or in a borehole. The pipe if filled with a mixture of water and antifreeze. Secondly a pump is used to pump the mixture around the pipe where it absorbs heat from the ground. Thirdly there is the distribution system which is normally in the form of under floor heating or radiators. In some cases water storage for hot water supply is also included.

The ground source pump has three elements an evaporator, compressor and a condenser. The pump of course requires a supply of electricity to operate it. Both the type of property and heating requirements will have a bearing on the different options adopted in terms of the type of loop. Boreholes tend to be used where space is limited, but where there is space available then a trench can be dug and either a horizontal or spiral loop inserted. A ground source heat pump can provide 100% of space heating requirements, but will usually only pre-heat domestic hot water, so top up heating with an immersion heater is required.

The cost to install a ground source heat pump in the UK range from £8,000 to £12,000 depending on the property and location. There are a number of advantages. It will be cheaper to run than gas, oil, LPG or electric storage heaters. The payback on this type of space heating will depend on what type of fuel is being replaced. It would for instance be well suited to a location where there is no mains gas supply. The pollution with this type of heating will be less in terms of CO2 emissions than even the most efficient gas or oil boilers.

A ground heat pump whilst providing green energy in the form of heat from the earth, requires electricity to operate the pump and if this supply of electricity is provided by fossil fuels then the system is not 100% green. It will be necessary to source a green supply of electricity. However even without green electricity, the emissions will still be less than with other heating systems. Some grants are available for this type of heating and it should certainly be considered if funds and space is available.

Hi,

The devastation of the gulf of Mexico following the explosion of the BP oil rig must surely raise some fundamental questions. Is it not time to stop deep sea drilling for oil? I hope that President Obama will now outlaw it off the coast of America.

But there is a far more fundamental question here, why do we continue to search for fossil fuels that we know damage the environment? Whilst I accept that BP must not be allowed to go bust due the dependence of investors in the UK and USA, it is surely time to reconsider energy sources.

Do not tell me that we cannot develop a new non poluting fuel. If we can put a man on the moon then we can provide a new source of energy. The source must not be nuclear or from growing crops.

I suspect the real reason is vested interests. The oil cartel obviously enjoy holding the world to ransome, but how long are we going to put up with it. Fossil fuels will eventually run out, it is time to start accellerating plan for new energy. Hopefully this disaster will make those in power re-examine just where we are going with energy resources.

Geothermal energy starts with hot molten rock called Magma miles below the earth’s surface that heats a section of the earth’s crust. The heat rising from the Magma warms underground pools of water known as geothermal reservoirs. These reservoirs can even boil to produce steam and if there is an opening in the rock to the surface the hot water seeps out to form springs, or it may boil to form geysers.

This type of energy only occurs in certain areas of the globe where the earth’s crust is geologically unstable. Places like Chile, Iceland, New Zealand, United States, the Phillipines and Italy. People have been using hot springs for bathing and cooking food for thousands of years, but it is only relatively recently that it has been considered as a source of energy. In a similar fashion to solar thermal electricity, steam is pulled directly from the reservoir or from water to make steam and piped to a power plant where it turns a turbine to generate electricity.

Geothermal energy is a green source of energy in that it does not harm the environment. However there is some debate as to whether it is renewable. Should the rate of use of the steam from the reservoir be excessive then the reservoir may not have the ability to replenish itself. One additional problem is that the fact that water from geothermal reservoirs often contains minerals that are corrosive and polluting and so these need to be managed.

This form of energy is unlikely to be a green source for domestic use, but certainly where these reservoirs exist it makes sense to utilise the steam from them to generate electricity. It is for instance likely to be a much more acceptable method of generating electricity, than by coal fired or gas fired power stations. The environment will also suffer less pollution.   

In many parts of the world people have been producing energy from Biomass for centuries. In some areas it is still the main source of heat. The energy from Biomass is produced from organic matter of recent origin. The CO2 released during the generation of energy from biomass is balanced by the CO2 absorbed during the fuel’s production. The process is therefore said to be carbon neutral.

There are two categories of bioenergy, firstly forest products such as untreated wood, energy crops which are used for stationary heat and electricity generation. Secondly biofuels are made from animal wastes, industrial and biodegradable products from food processing as well as high energy crops such as rape seed, sugar cane and maize. These biofuels are mainly used for transportation.

Biomass for domestic applications takes the form of wood logs, wood chips and wood pellets which are used in wood burning stoves. This is a green source of energy as it is renewable. There are two ways that biomass is used to heat domestic properties. Firstly stand alone stoves which provide space heating for a room. Some models can be fitted with a back boiler to provide water heating.

Secondly wood burning boilers connected to central heating and hot water systems. Wood burning stoves can achieve efficiencies of more than 80%. Unlike gas or electric stoves of course you are required to buy fuel to put in the stove. However this is going to be much less expensive than gas or electricity and it is carbon neutral.

Wood burning stoves in many areas are the stoves of choice providing that your home is located near a forest or supplier of wood pellets. If wood or pellets have to be transported some distance , then this form of energy is no longer carbon neutral due to the carbon produced by transportation.

Whilst it is acceptable to turn animal waste and industrial waste into biofuel for use in transportation, the growing of crops like rape seed is controversial. The Governments of the European Union had in recent years a policy of requiring fuel for transportation to be made up of 15% biofuel, they have now had to reduce this to 10%. The reason is that farmers were switching from growing food crops to biofuel crops to the detriment of the food supply chain.

In areas where there are forests or wood pellet suppliers the use of wood burning stoves should be encouraged in order to protect the environment.

Learn how to build your own green energy

Hi

   You may well have heard that companies working on carbon-capture and storage for coal-fired power stations are developing equipment to separate the CO2  and then pump it down pipes into caverns under the sea.

In the meantime a UK Government backed company the Energy Technologies Institute is looking at a revolutionary way to capture climate-changing gases including CO2 from coal as it is burnt and bonding them into materials that can be used to make bricks. This company is working with Shell to investigate the technology further.

Apparently scientist working at the Energy Technologies Institute discovered that certain minerals and CO2 can react together to permanently store CO2 as solid carbonate products. It may take years to see if this brick-making technology will be effective, but at least it looks like an improvement on piping the CO2 under the sea. 

Hi,

Good News! The new coalition Government in the UK plans to promote a multi-billion pound industry converting waste into energy with the aim of providing 4% of the country’s energy needs within ten years.

The plan is to use anaerobic digestion plants. Apparently these are large containers that can be fed food waste,maize slurry and sewage. This plant and animal material is digested by micro-organisms which releases methane. this can then be used to provide light and heat.

It is hoped that this method could supply two million homes with power. There have already been anaerobic digestion plants on farms for many years., and it is hoped that if a viable anaeobic digestion industry is developed, that it will not only provide energy , but also may solve the problem of landfill sites which is a growing one.   

        Imagine if you could have hot water all year round and at the same time reduce your electricity bill. Well it is achievable if you have a solar hot water  collector to collect the energy from the sun and heat your water.

I am sure you have heard of harnessing the power of the sun to generate electricity using solar panels with Photovoltaic cells. The other type of solar panels to heat water use solar hot water collectors. There are two types, evacuated tubes and flat plate collectors. Both types are fitted to the roof of your home to collect energy from the sun and heat the water which is stored in your hot water cylinder.

Is your home suitable for installation of a solar hot water heater system? The first first consideration is the location of your home, is it exposed to the sun? If you have a pitched roof and your house faces South then you can place a single solar hot water collector on the South facing slope, if you face East/West then you will need one on each slope of the roof for maximum exposure to the sun.

Most houses are suitable for installation of solar hot water collectors, and it does not matter what type of boiler you have it should be compatible, the only exception is if you have  a combination boiler (combi) and do not have a hot water cylinder then it may not be suitable. One thing you will need with a solar hot water system is a larger hot water cylinder, so you need to have the room to install it.

You will not need planning permission to install your solar hot water collector, and maintenance is very low. Most importantly you can save up to a third on your electricity bill and enjoy piping hot water throughout the summer months. You will not have to use your boiler to heat the water, but can use the emersion heater in your cylinder for short periods when it is a dull day.

If you go to one of the estabished Solar companies you will be charged thousands of dollars in the UK from £3,000 – £5,000. When I fitted my solar hot water heater system it cost me over £6,000. That was almost 4 years ago. The good news is that you can now build a solar hot water collector yourself for less than $100. 

You can obtain a detailed instruction manual online for around $37 and you can get the components for less than $100. The system can be built at home in a few days.I can highly recommend a solar hot water system, I can honestly say that it is one of the best additions to my home.  find out how to build your own solar hot water heater system

Hi,

         In view of the almost weekly rise in the cost of Petrol and Diesel fuel, it is good to know that scientists are working on producing fuel from air. Researchers in Japan and America are already working on this idea. This week we hear that scientists from three UK universities, Bath, Bristol and the West of England have been given a grant of £1.4 million to research taking carbon dioxide from air and mixing it with hydrogen to produce fuel.

The idea is to take carbon dioxide out of the air and turn it into chemicals, fuels and plastics that are derived from hydrocarbons. The first process is to suck carbon dioxide out of the air and the second process is to develop a way to produce hydrogen other than from water by electrolysis or methane. The suggestion is that algae  could feed on light and the carbon dioxide extracted from air to produce hydrogen biologically.

Perhaps in the future we will have carbon dioxide refineries rather than oil refineries. Lets wish them success and hope they can produce this fuel from air in a reasonable time frame before we all go broke paying for our petrol and Diesel.

Hi,

          Apparently leading gas-producing nations are meeting this week in Algeria to vote on cutting supplies of gas. It seems that they wish to double the price of natural gas. They have been deliberating on reducing supplies for years but this is the first time they have agreed to have a vote.

Whilst it is unlikely that they will agree to cut supplies this time around, it is nevertheless an ominous sign. It is bad enough that the oil cartel have been holding us all to ransome for years without the gas cartel following suit.

To my mind it is yet another reason to start using natural resources of energy like wind power and the power of the sun. Now is the time to find out what particular source of energy suits your home. You may be able to heat your house with a wood burning stove which is carbon neutral.

Use either wind power if you have sufficient wind speed and or solar panels with photovoltaic cells to generate electricity, and solar panels to heat your water.

Hi,

          If you live in the UK then you may well have been encouraged by one of the power companies to switch to green electricity. However there is now some controversy about this due to the fact that you do not really know how much of electricity you are getting is generated from renewable resources.

The present law is that 9% of energy generated by any power company in 2008/2009 must come from renewables. For each unit of renewable electricity power companies are issued with a “Renewable Obligation Certificate”.  However the controversy comes because power companies who generate in excess of 9% renewable energy can sell their excess certificaters to those who have not yet reached the 9% level. Sounds highly suspicious to me.

It is no wonder the regulator is now looking into this matter. If you choose a green tarif from your power company I suppose at least you may be getting some of your electricity from renewable resources, but the very best way to get green electricity is to generate it yourself from the power of the sun in your own home using solar panels. Not only will you be using green energy but you will be saving yourself anything from 30% to 80% on your electricity bill.