POND WEED

ENERGY FROM POND WEED

Pond algae are so effective at harnessing energy from the sun. Some purple bacteria uses light energy with almost 95% efficiency. More than four times more effective as a solar panel. It might not be too long before this “primitive” pond life will be heating our homes!

Environmental.

RENEWABLE ENERGY

Photo: A section of a wind turbine being delivered to Carndonagh.

Ian .


I hear a lot about different types of renewable energy. Could you explain them to me? Can I use any of them in my own house? Regards AN. Buncrana

Reply.
Modern societies consume huge amounts of energy. Heating homes and offices, fuelling transport systems, powering industry and generating electricity. Ireland is no exception; and as our economy grows, so does our demand for energy.

RENWABLE ENERGY
Today, most of this energy is produced using fossil fuels such as gas, oil, coal and peat. These are finite resources -which will one day run out. Burning them releases vast quantities of carbon dioxide, a potent greenhouse gas, into the atmosphere. Other emissions released in fossil fuel combustion cause acid rain. Ireland now imports over 85% of the fuel required for energy production. Renewable energy resources, on the other hand, are constantly replenished through the cycles of nature. The sun, wind, running water, organic materials like wood and even wastes from domestic and agricultural activities are all potential sources of energy. Their supply will never be exhausted.

Several renewable energy technologies are now commercially viable and could make a much greater contribution to sustainability in our energy supply. Renewable resources with the greatest immediate potential in Ireland are wind and biomass energy (wood) for electricity generation. Biomass, geothermal and solar energy could be used for heating. Using wood fuel to heat our homes is a sustainable choice. Wood is 'CO2 neutral', absorbing as much CO2 when it grows as is released when it burns, and takes just 5-20 years to grow. Modern, highly efficient stoves and fireplace inserts make wood fuel a far more practical option for today's lifestyle.

Great potential
There is great potential to use forestry and agricultural energy crops in Ireland and short-rotation forestry offers further potential for the future. Another form of biomass fuel is decomposing municipal waste. This produces gas, which at present provides around 15 MW of electricity in Ireland- enough for over 19,000 homes.

Renewable resources currently provide around six percent of Ireland's electricity capacity. More than two thirds of this is in large-scale hydropower stations operated by the ESB.

Wind energy could make a far larger contribution to our electricity supply. Ireland has one of the best wind resources in Europe. The technology is well proven as safe, reliable and cost-effective (some people also think them an eyesore!). Modern turbines are quieter than ever and you can even get miniature turbines that fit on your chimney. A single 1 MW wind turbine produces enough electricity for 650 homes. The one on your chimney can power your own electrics.


Heat from renewables
The use of renewable energy such as solar panels to provide sustainable heating (and cooling) in commercial and residential buildings could also be greatly increased. Just by facing a house south to capture the maximum sunlight, energy bills can be reduced by ten percent. With additional measures this saving can be trebled. Heat pumps offer an ideal solution for heating and cooling in homes and commercial buildings in Ireland. Geothermal pipes placed under the ground in the garden collect and concentrate geothermal energy stored in the earth to provide space and water heating. The energy can be used to dispel heat for air conditioning. Installation costs are similar to those of conventional heating systems; running costs are much lower. Active solar heating systems can provide economical hot water and space heating. In Ireland solar panels can provide around 60 percent of the annual hot water requirements for homes and buildings. Solar resources in Ireland are considerable (comparable to those in the Netherlands and Austria) and yet remain undeveloped to a large extent.

( For more information click on the title for a link to the Sustainable Ireland web site)





Environmental.

SOLAR COOKERS

SOLAR COOKERS

Thousands of years ago the Greeks and Romans realised that the sun is the great source of heat and light for our world. They designed their homes and cities so that everyone would benefit from its inexhaustible energy. The sun was at the heart of their lives.

Today, solar cookers are the prefect way to harness the pure power of sunlight. All that is needed for a simple cooker is an old pizza box and some silver foil; it’s as easy as that. The easiest method is to put the foil on three or four sides of a box and angle them inwards to a central point where the pot or pan is to cook the food. Of course there are hundreds of different designs to choose from but the principle is the same. Redirect the heat energy from the sun directly to the food that you want to cook. For centuries people in hot, sunny climates have realised the sun’s energy. Fruit such as grapes, tomatoes and mango are all dried using the sun. If you have ever used a magnifying glass to focus the sun’s rays you will know how powerful the sun is.

Build your own solar panels....

Saving trees

Horace de Saussure, a Swiss naturalist experimenting as early as 1767, invented the first solar cooker. The principle is still the same today. Using solar cookers in hot underdeveloped countries could have very positive effects on the environment. The fumes from fires that are used in open fire cooking are responsible for millions of premature deaths a year. The decimation of the local woodlands and forests for firewood deprive the people of shelter for animals and building materials and greatly reduce the bio-diversity of the land causing famine and disease.

The solar box cooker has been hailed as a simple answer to some serious ecological problems. Using these instead of open wood fires can save millions of trees, provide clean, safe drinking water, doesn't cause smoke, and costs very little

Research has found that 36% of the world's fuel wood needs (or 350 million tonnes of wood per year, according to UNICEF) could be replaced by solar box cookers, saving 500 kg of wood per family per year, equalling millions of trees.
I'd put my money on the sun and solar energy. What a source of power! I hope we don't have to wait 'til oil and coal run out before we tackle that. Thomas Edison




How hot do solar ovens get?

Heat isn’t the issue here, as long as there is twenty minutes of sun in each hour the devices will work effectively. Mountaineers take them and boil their water in sub zero temperatures for example. The temperature reached by box cookers and panel cookers depends primarily on the number and size of the reflectors used. A single-reflector box cooker usually tops out at around 150° C (300° F) as the food approaches being done. High temperatures, however, are not needed for cooking. Your oven will cook just fine as long as it gets up to about 90° C (200° F) or so. Higher temperatures cook larger quantities, cook faster, and allow for cooking on cloudy days; However, many people prefer to cook at lower temperatures, since then they can leave the food to cook while they go about their business. With a single-reflector box cooker, once the food is cooked, it just stays warm and doesn't scorch. It's good to keep in mind that no food can go above 100° C (212° F) anyway, until all of its water content has evaporated. The high temperatures you see in cookbooks for conventional ovens are just for convenience and for special effects such as quick browning.


If solar ovens are so good, why isn't everyone using one?

There are many factors at work here. First and foremost, the vast majority of the world's population does not even know that it is possible to cook with the sun. When they find out about it there is almost universal enthusiasm, especially in regions where the gathering of cooking fuel and the process of cooking over a smoky fire is a great burden. There are many factors that need to be in place to make it possible for poor people to solar cook on an on-going basis. The most successful projects have been ones where the need was the greatest, the weather the most favourable, and where the solar cooking promoters have taken a long-range approach to the transition.

Here in Ireland we will be able to use the solar box method of heating our food throughout the summer. Barbeques on the beach could be a whole new experience. As soon as the cooking is done and the panels turned away from direct sun, the box is cool and ready for putting back in the car.

Environmental.