An equivalent opportunity to change the world energy system has not presented itself for nearly a century. The move toward fossil fuel energy in the early part of 20th century was marked by transforming of cities all over the world as automobiles and electric bulbs replaced horse-drawn carriages and gas lamps and this overdependence on it is proving to be self-defeating as can be seen by the skyrocketing prices all over.
Compared to today if the miniscule play of knowledge factor brought about an explosion of invention and its application in an era when people were afraid to change their lifestyle, it would not be wrong to say today, with a world hungering for cheaper fuel and a collective conscious that prefers ‘Change’ a revolution is in waiting. Though the technology to harness fuel has increased drastically it has failed to reflect on the cost apparently due to high demand, dwindling resources and the monopoly of a few, be it Hydro, Thermal, Nuclear or Fossils. None of which is green (Hydroelectric projects actually harms by displacing vast number of people from their original habitat and killing forest area)…
The environment is ripe for energy source that is not only cheaper but also will not deplete itself as we use it and is green. One of this energy sources is the Solar Energy. This vast, clean energy resource represents a viable alternative to the fossil fuels. Failing to take advantage of such a widely available and low-impact resource would be a grave injustice to our children and all future generations.
This site deals in Solar Energy for heating which is all that in U.K. and Ireland.
Total consumption of energy in Ireland is about 2.5 million tonnes of oil every year not counting transport. This represents 25% of the total final energy consumption in Ireland. Burning fossil fuels like coal, oil, peat, gas etc provides the vast majority of that energy. This results in the emission of 11 million tonnes of carbon dioxide, the main contributor to green gases emissions.
What is Solar Energy?
Solar Energy, radiant energy produced inside the sun at extreme high pressure causing nuclear fusion resulting in a temperature in excess of 5000 oC. This energy is radiated out in the form of light and heat. Most of the energy that earth receives is in the form of light and takes about eight minutes to travel the distance. By the time it reaches Earth’s surface, one third is absorbed by the atmosphere. Scientific calculation has deduced that almost an energy equivalent of a barrel of oil (4.2 kW) is collected over each square meter of earth’s surface. All the energy stored in Earth’s reserves of coal, oil, and natural gas is corresponds to energy from just under a month of sunshine. This is enormous amount of energy. And it is free. Today technologies such as Solar collectors, sit on the rooftops of buildings to collect solar energy for space heating, water heating, and space cooling (desiccant evaporators, absorption chillers), Solar Thermal Concentrating Systems, parabolic troughs, parabolic dishes, and central receivers, Photovoltaics are some of the few highly efficient systems available.
How is Solar Energy Harnessed for Heating?
Solar energy applications can be grouped into there are three primary categories: heating/cooling, electricity production, and chemical processes. The most widely used applications are for water and space heating.
Solar Water Heating should not be confused with directly generating electricity from the sun using photovoltaics (PV). Over 70% of the average household’s energy use goes into space and water heating.
Solar Water Heating uses the radiation from the sun to heat water in a panel often sits on the roof at an angle of between 20 and 50 degrees facing south which in turn can supply that heat as hot water or to a central heating system, In Ireland an optimum sized one can provide at least 40-60% of all hot water requirements throughout the year and reduces carbon dioxide emissions by around 400kg / year on an average domestic system. Two types of solar heaters can be used in this way.
The first is called a Flat plate collector, which pumps water (propylene glycol anti-freeze added) through a series of pipes enclosed in an insulated box with a glass panel on one side. A solar water heating system for an individual household will have an area of about 3-4m². When solar radiation passes through the glass, the energy absorbed is transformed into heat and stored in the water. Heat is diffused through water and gets heats progressively. This heated water then moves on to a separate storage tank where it retains its heat and is pumped into as needed.
Evacuated solar collector, which consists of a row of vacuum solar tubes and a highly insulated manifold. Heat transfer fluid is circulated in a coaxial manner through the manifold and tubes. Insulation and vacuum ensures minimum energy loss while transferring efficiently and effectively. Efficiency of 60% is achieved. Evacuated tube collectors are more efficient and -hence occupy less space compared to the Flat Plate collector- with higher water temperature and can provide solar water heating when solar radiation is less intense (will perform considerably better than the Flat plate ones under widely common cloudy, cold and windy conditions in the UK and Ireland). Most customers have appreciated this desirable feature of less area covered by these flat glass covered boxes. Moreover many of these products available in the Irish market have been designed for flexible building integration, and can be installed on a sloping roof, vertically or horizontally. The average household with a 3m2 system installed can expect to generate approximately 2,000 KWh/year with zero Carbon emissions.
What are the main components of a solar water heater?
A solar water heater is manufactured and installed to last at least a lifetime of 25 years. Typically a Solar water heater will have the following parts
1.A component to collect solar radiation (sunlight) and change it into heat called the Solar Collector
2.A heat transfer equipment (to transfer heat from the collector to hot water in a storage tank.)
3.The Hot water storage tank
4.Safety accessories and regulators to control the system.
5.A back-up heater (gas or oil boiler, immersion heater, heat pump) as in Ireland they are usually installed in combination with a conventional heating system.
What is the current profile of Solar Energy particularly for heating in U.K and Ireland?
Solar heat can be utilized to produce hot water or to warm buildings via a hot air or water system. In solar water-heating systems, heat from the sun is absorbed by a solar collector and transferred to the water directly, or via a working fluid. People in U.K and also in Ireland believe that they receive less sunshine, which is not true. Ireland gets half the solar energy received at the equator which is more than enough to operate a solar water heating system. The average Irish home requires approximately 3000 kWh per year for hot water heating. Over the year, a typical solar water heating system in Ireland provides 50% to 70% of this annual domestic hot water requirement (roughly 90% in summer, 50% in spring, and 20% in winter). A solar energy system provides heat input even on cloudy days by using energy from diffused light.
Even in winter, the system will pre-heat the water in your cylinder, which will make a significant reduction to your gas, oil or electricity consumption throughout the year. In fact Ireland receives more than five hundred times the total amount of energy it consumes annually. In Ireland a horizontal surface of 1m2 receives from 1,000kWh to 1,200kWh of solar energy per year (the equivalent of 120 liters of oil). It receives both direct sunlight (40%) and indirect sunlight (60%). Even on an overcast day the sun’s radiation (sunlight) which is available at ground level can be harnessed so one need not say anything about sunny day- it is estimated that a power equivalent to that of 10 strong bulbs can be had on any day in Ireland. Ireland has around 3,500 square meters of solar thermal collectors installed representing just 0.2% of the estimated practical solar heating resource available now. An average Irish family will spend over IR€ 2,000 at current energy prices every year to heat their home. Commercial and public buildings represent 15% of Ireland’s total final energy consumption and emit over seven million tonnes of carbon dioxide every year (one fifth of Ireland’s total). Nearly 70% of that energy consumption is on cooling, space and water heating. This can effectively be cut by 35% to 45% at no extra cost by harnessing solar energy and without emitting a single molecule of Carbon by way making the energy available.