While building a house we can also plan for tapping a source of energy that is absolutely free - the sun. Except for some initial expenses which involve setting up of solar panels and related equipment solar power can generate income besides fulfilling our energy needs.
We need to take care of certain aspects while installing the solar panels. The first point to note is the position of the panels. They have to be installed at a spot where direct sunlight is available. The solar energy tapped by the panels is converted into direct current (DC) which can be stored in a battery and later used for domestic purposes through an inverter. About 100 units of power can be obtained from a solar power system of one kilo watt capacity.
Ten square metres of space needs to be set apart on the roof for the panels. Inclined roofs are also suitable for the purpose. The panels have to face the western direction and factors like the path of the sun over the house, shadow of other buildings and trees also need to be taken into consideration.
Many people have a false notion that solar power is suitable only for working a fan and a couple of lights. But the reality is that the motors, heaters, air-conditioners and other heavy electrical equipment can also function on solar power. There are houses which have not even applied for power from the Kerala State Electricity Board (KSEB) and are totally dependent on solar energy.
The solar panels have to be connected to appliances that are used the maximum. Before that, the connected load has to be calculated. Each appliance has a specific starting current as well as a running current. The starting current would two or three times the running current. Both these figures need to be taken into account for calculating the connected load.
On-grid and off-grid
There are two types of inverters – on-grid and off-grid. On-grid inverter allows supply of the excess power that remains after our use to the KSEB. An application has to be submitted to the KSEB for installing this facility along with a fee of Rs 1,000. Officials will conduct an inspection and in case everything is in place, they will allow us to supply electricity to the government. The cost of this power will be deducted from our electricity bill.
The biggest advantage of on-grid system is that the expenses on battery can be avoided. However, the disadvantage is that in case there is no power in the KSEB grid when we need electricity, we will be helpless.
A battery for the solar system would cost around Rs 20,000. The battery should be selected on the basis of the amount of electricity used in the house and time of back-up needed. For one hour back-up, a 1,200 Watt Hour battery would be sufficient.
Care has to be taken while choosing the capacity of the solar system also. For a four-member family using an AC, a three-KW system is ideal.
This produces up to 12 units of power. During the rainy season, the output would be around six units. The expenses for setting up such a system with on-grid facility would be between Rs 2.50 lakh and Rs 2.75 lakh. It includes the panel, inverter and surge protection unit. Break-even can be achieved in five years by saving the amount of the electricity bills.
Off-grid requires changing of the battery and is not as economical long-term as the on-grid system. This has made on-grid system more popular.
There is another misconception regarding solar power, that is more solar power can be produced during summer. According to experts, the efficiency of the silicon cells in the solar panels falls as the temperature rises. The ideal mercury reading for the cells to function at the peak level is 25 degrees Celsius, point out the experts.
Solar plant, like any other electrical equipment, needs regular maintenance for efficient functioning. The panels have to be cleaned once in at least two months. Otherwise, dust and dirt will accumulate over it, affecting the output. In addition, lighting conductors and quality earthing too have to be set up.
It has been found that at least 60 per savings can be made on the power bill if the solar system functions efficiently. This makes the installation of a solar system, which offers free electricity, imperative.
