All the energy we use comes from the earth. The electricity we use every day doesn't come directly from the earth, but we make electricity using the earth's resources, like oil, coal and gas. These are called “fossil fuels” because they were formed deep under the earth during dinosaur times. The problem is that fossil fuels can't be replaced - once we use them up, they're gone forever. Another problem is that fossil fuels cause pollution. Renewable energy is made from resources that nature will replace, like wind, water and sunshine. Renewable energy is also called “clean energy” or “green power” because it doesn’t pollute the air or the water.
Unlike natural gas and oil, we can’t store up wind and sunshine to use whenever we need to make more electricity. If the wind doesn’t blow or the sun hides behind clouds, there wouldn’t be enough power for everyone. Another reason we use fossil fuels is because they’re cheaper. It costs more money to make electricity from wind, and most people aren’t willing to pay more on their monthly utility bills.
A carbon footprint is a "measure of the impact that human activities have on the environment in terms of the amount of greenhouse gases produced, measured in units of carbon dioxide". These gases are produced by the burning of fossil fuels for our everyday living. For example - heating and electricity. The term owes its origins to the idea that a footprint is what has been left behind as a result of the individual's activities. Carbon footprints can either consider only direct emissions (typically from energy used in the home and in transport, including travel by cars, airplanes, rail and other public transport), or can also include indirect emissions (including CO2 emissions as a result of goods and services consumed).
It’s another way to say “saving energy” - “conserve” means to “avoid using.” When we turn off a light, we’re conserving energy.
Energy efficiency also means using less energy – but this term means using products that don’t waste energy. For example, the ordinary light bulbs you might use at home waste almost all of the energy they use – most of the electricity turns into heat. An energy-efficient light bulb turns almost all of the electricity it uses into light.
FAQs – RENEWABLE ENERGY AT HOME
At a domestic level, solar power can be used in two different ways: solar water heating & Photovoltaics (PVs). Solar water heaters utilise the sun’s energy in order to provide hot water, whilst photovoltaic panels convert light from the sun to electricity for use in the home. Both types of domestic-scale solar power will reduce your dependence on electricity from the grid and reduce your bills to the utility and will also significantly reduce the CO2 emissions from your home, lowering your ‘carbon footprint’.
A solar water heater uses the energy of the sun to heat water. An adequately sized and properly installed solar water heating system can provide a typical home with nearly all the required hot water over a year. That will be a massive saving on your electricity consumption! The solar water heating system works by using solar collectors which are usually positioned on the roof of the home. For maximum efficiency the panels should face south and should not be overshadowed by buildings or other obstructions. A typical installation would only require about 4m² of roof space so will certainly not be an eye sore. There are three main components to a domestic solar power heating system; the solar panels, a heat transfer system and a hot water tank. Photovoltaic panels can be used to provide your home or business with solar electric power. The sun’s energy is harnessed and turned into electricity which can then be used within the building to provide power for appliances and lighting. Solar electric power is an ideal way of utilising a renewable energy source and minimising your use of other, less environmentally friendly fuels. Wherever possible, PV panels should face south and inclined at 33° to the horizontal. Buildings are suitable for solar electric power if at least 10m² to 15 m² of available roof area is not overshadowed by other buildings or other obstructions. The photovoltaic panels are available in a number of technologies such as crystalline and thin-film, both of which are suitable for use in Malta.
The cost of 1kWp (peak power) solar electric power which is adequate for domestic use ranges from approximately €5000 to €7,000 and should harness enough power to cover approximately 20% of your annual electricity consumption. If the PV system is instantaneously generating more power than is being consumed at your home, the excess energy is exported to the national grid. Panels are to be kept clean especially during summer in dust-laden environments to ensure an optimal yield. Solar electric power systems not connected to the national grid will require additional maintenance on other system components such as batteries.
In Malta we are blessed with very high levels of sunshine and we have the highest level of solar irradiation in the EU and this contributes to a high level of performance from solar water heaters. Malta is right in the center of the Mediterranean and therefore we experience adequate sunlight for around 80% of the year. A good comparison is that a user of solar water heaters will save over 80% of the cost of running an electric boiler. For an average family of 4 which uses solar heated water for all its needs this will translate in savings of €300-€500 annually.
There are two types of solar water heaters available on the market, the flat plate collectors and the vacuum tube. The difference in design is mainly due to the insulation used from one type of solar panel to another; flat plate collector uses polyurethane to insulate their panels whereas the vacuum tubes will use the vacuum itself (thermos effect) to insulate the tubes. The flat plate collectors are generally less expensive, but are a little less efficient in the winter months. The vacuum tube collectors can reach higher temperatures, and whilst this is not at all necessary in our summer months, they do achieve a better temperature in winter too.
The answer is yes, however it is unrealistic to expect that all that hot water will be supplied from the sun for free! There are actually two reasons for this; the first is that if one uses all the stored hot water at night or late evening, there is no sun to reheat the water. The second is that there will be days in winter where the light intensity is too low to heat the water up to a level used for washing. The electrical backup element will therefore have to be used sparingly in winter. Good solar water heaters are also usually supplied with a control system that allows the hot water level to lower before allowing the entry of cold water. This is particularly useful to ensure that hot water is still available in the morning even if some of it is used in the previous evening.
UV (ultraviolet light) is often mistakenly thought to be the magical part of the sun’s radiation which heats water! UV is only a small part of the whole light spectrum and will not heat water on its own. It is the intensity of the whole spectrum of the light which will heat water – the more intense, the more hot water from your solar heater!
If you have a solar water heater, with an electric booster (heater), make sure that the booster in winter only comes on after sundown or preferably very early in the morning before use, to avoid heating the water before the sun has had a chance to do so. Install a timer and set it accordingly.
Basically P.V.s are made up of a number of cells grouped together to form modules. The power rating of each module varies from say 50W to 180W. This depends on the type of material and technology used. Strings of modules are grouped together to form systems ranging from a few hundred Watts to Kilowatts (1000 Watts) and even to Megawatts (1,000,000 Watts).
10 square metres of solar module area are typically required for 1 kW of power. Typical dimensions for a 100W module are 1500mm x 600mm x 40mm. Typical weight is 11kg.
The cost of P.Vs is still high compared to other renewable energies, but have come down considerably over the years. Typical cost for a 1 kwp (1000 watts peak) unit varies from a minimum of € 5000 when supplied in large quantities to a maximum of €7000. One has to shop around for prices. A P.V. system generates electricity while the sun is shining and does not generate electricity during the night. There are two possible methods of connecting P.V. systems; stand-alone or grid connected. The stand-alone systems are often used in remote areas where there is no electricity grid available and are supplemented by batteries. The latter are charged during the day while the sun is shining and discharged during the night when they are used to light bulbs say. Grid connected systems are connected in parallel with the electricity grid. In this method the customer is supplied with electricity from the grid during the night while during the day electricity generated by the P.V. system is partly used by the customer and partly exported to the grid. A grid-connected system is normally cheaper than a stand-alone system because there are no batteries involved.
You can use PV systems for a building with a reasonably sized roof as long as no other buildings or other obstructions overshadow it. If the roof surface is in shadow for parts of the day, the output of the system decreases dramatically and one may not recommend to install a photovoltaic system. For further information please consult an engineer or an expert.
This might be possible, the only limitations are that the roof must be large enough and the area must have no shade within the area where the solar panels would be installed. An area of 10 square meters are typically required for 1 kW of power.
Yes, these are called 'grid-tied' systems, which means that any unused electricity bill be 'given' to Enemalta. These units of electricity are metered and refunded by Enemalta on a net basis.
In order to be able to connect to the grid the customer needs to submit an application form “Form PV” (click here to link to PV Form) to Enemalta which is also available on this website.
A special electricity meter is installed by the electricity utility. The present system being adopted in Malta makes use of a meter which measures in both directions i.e. it measures electricity imported from the grid and used by the customer and it measures as well surplus electricity generated by the P.V. system and not used by the customer and which is exported to the grid. The meter has two registers to measure imported and exported electricity separately.
The customer pays on a net metering basis, that is any units exported to Enemalta will be deducted from the units imported. Additional units consumed above those exported will be charged at the published tariffs (click here to link to tariffs) . In the case where the units generated exceed the units imported, the consumer will be credited at Euro 0.0699 per unit. Energy balance is calculated on a yearly basis.
The Company will be taking actual readings of both the imported and exported units every six months. Whilst the imported units will be billed in the usual manner, a credit will be given for the exported units. The credit for exported units will not feature on the provisional bills but on the actual bills that are issued every six months.
This depends on the size and type of system installed. The amount of electricity provided by the solar panels is determined by the type of consumption that a user would have. An engineer or an expert can help you in determining what system size would be appropriate. A PV installation using crystalline technology is expected to produce 1550kWh of energy every year in Malta although the output can be expected to degrade to 80% of its initial output after 25 years.
All PV installations require approval or notification from Malta Resource Authority and also require approval from Enemalta prior to connection to the grid. MEPA permits can be requested in certain types of installations - the height and visibility can be requested criteria for a MEPA application.
The cost of installing solar PV costs between €5,000 and €7,000 for each kilowatt peak or kWp (the maximum power produced under ideal conditions). A typical domestic installation can be anywhere between 0.8 to 2 kWp. A solar PV system mounted on a south facing roof can generate 1550kWh per kWp each year.
A micro-wind turbine uses wind to rotate the blades that turn a generator at the top of the wind turbine. The electricity is fed into an inverter to be able to supply a residence or commercial building.
The conditions for a wind turbine in Malta are particular and an expert/engineer would need to be consulted to conduct a site assessment to determine the viability of the micro-wind turbine.
The two most important parameters to determine the amount of electricity that can be generated from a wind turbine is the average wind speed of the site selected and the size of the wind turbine. For further information please consult an engineer or an expert.
Yes, MEPA must be consulted before installing a micro-wind turbine in Malta.
Yes, a micro-wind turbine will make some noise that may disturb the owner and neighbours. However, every moving or rotating object will create 'noise', e.g. air conditioners, fans etc. Different types and brands of wind turbines will create different noise levels, and the supplier should be consulted.
If you are considering using renewable energy in your home then you may be considering a domestic micro-wind turbine. A domestic wind turbine can be fitted to your house or in a suitable location very close to the building, and the energy derived from it will go towards powering your home.
In order to fully power a modern home, the domestic wind turbine would need to span five metres from tip to tip on a site with good wind conditions. The average 4 person household consumption is approximately 4500 KWh and a domestic wind turbine with a span of two metres might yield 500 kWh per year in good conditions. The energy produced by the turbine can be used to charge batteries or be connected to the national grid. In many cases homeowners use a domestic wind turbine to supplement the energy they receive from the national grid, thus reducing their bills but not being entirely reliant on the wind power.
If you wish to install a domestic wind turbine, the first thing to establish is whether there is enough wind at your location for it to be a viable option. Also check whether there is enough space and whether the structure of the building is strong enough to withstand the forces generated by a micro-wind turbine.
Rural areas tend to be better sites for domestic wind turbines than urban areas due to issues with buildings blocking the wind.
Where can I find information on the Government Energy Saving Support Schemes that were launched recently (Feb’09)?
Information on these support schemes for solar water heaters, photovoltaic panels, roof thermal insulation and double glazed windows and doors can be found at the Malta Resources Authority link below: Malta Resources Authority