The Sunday Mail
Takaendesa Denhere
Solar energy provides a viable alternative to conventional energy.
Our energy deficiency has reached levels that are not acceptable. Homes, service providers and firms are going for hours without electricity. Worst affected are households that are going for several hours without power, just imagine getting access to electricity only during the night.
But the power utility appears unmoved.
They always have good explanations and excuses. From the current configuration, we are going to have this situation for years. Some are now planning to wean themselves from the power utility and I am here to help plan your way out of the bondage of the power utility.
In this article, PV refers to photovoltaic modules commonly known in Zimbabwe as solar panels and PV energy refers to the energy generated by the panels.
Your next option after the utility supplier is establishing an independent home solar electric system. There are a lot of advantages to this system like, provision of energy security, cutting off monthly energy expenses. Solar energy also provides energy security for all the homes that use the sun as a source of energy. There are two main types of solar installations in residential areas. The first and most common system is called the grid connect system which connects your solar installation to the main electricity grid. This grid allows you to feed excess energy back to the grid through your meter and be financially rewarded for it by your energy company.
It is not yet applicable in Zimbabwe, though common in countries like the US, Australia, and India. I focus on the stand-alone solar power system which is applicable for remote properties where the cost of connecting to the utility grid is prohibitive. It can also be used even in areas that are connected to the grid as a backup system or a fully solar electrified house.
The first step that you need to take is to find or choose a proper, credible contractor. You may be able do this on your own or maybe try to use online tutorials but the bottom line is that you need expert’s advice and guidance to make proper and informed decisions. Ask about their work record, experience and licenses because there are bogus contractors who may fleece you of your hard-earned money.
Ask yourself the following questions: has the company installed an independent PV solar system? How many years of experience does the company have in installing PV systems? A contractor who has been in business for a very long time probably understands more how to work with customers and compete effectively with other competitors.
Decide yourself whether to use solar energy as a back-up system or to wean yourself completely from the utility, you have got to assess and evaluate so that you buy the proper required equipment.
Also to help evaluate whether the solar electric system will work for you, you should consider the following: your available solar resource – do you have clear and unobstructed access to sunlight for most or all of the day, throughout the year?
The size of the roof also matters to ascertain the system design and space – do you have a roof or a large area large enough to accommodate it?
This question help in site analysis to determine the amount of electricity generated at a particular site depending on how much of the sun’s energy reaches it.
Remember that before you buy a PV system, you will want to be sure that your site has enough solar energy to meet your electricity needs efficiently and economically so you have to consider both the geographic orientation and the tilt of your solar panels because both can affect your system’s overall performance.
Before we go to selecting the right solar system components to buy and sizing a PV system for an existing home we need to look first at how you consume power in your house. An evaluation needs to be done on the energy consumption trends and patterns so that you reduce your home’s electric use.
One of the first things that you need to do is to start performing a load analysis which may include the following tasks: looking at your utility bills over the past year, calculating energy consumption and recognising your consumption trends.
By understanding your energy habits and becoming more energy efficient, you can reduce the size of the PV system you will need, lowering both your capital and operating costs. There are some home applications that have to be taken into consideration when building the home solar system which consume a lot of power.
By definition, applications are tools or devices which feed directly from the sunlight in order to produce the energy required to fulfill our everyday needs. The devices usually incorporate a solar cell that is capable of turning the sun’s radiation into electricity through a phenomenon called the photovoltaic effect.
One of the biggest concerns people bring out is cooking. Can solar systems sustain hot-plate stoves or ovens? No. Not yet. Solar technology is still developing and at the moment it cannot sustain stoves, we hope we will get there soon. The problem with these applications is that they use electricity directly without converting it from direct current produced by solar panels into alternating current for consumption by our electrical equipment and devices (DC to AC).
So in relation to cooking at the moment people can turn to low-carbon energy systems with almost zero-carbon emissions like biogas, LP gas and charcoal.
The next buck stops at water heating. Geysers are not sustainable when looking at solar energy. Like stoves their elements use direct electricity so the next alternative offered by solar energy to that is solar water heating systems.
There are several types of solar water heating systems, they’re all made up of two major parts: the solar collector and the storage tank. The collector is mounted on the roof-top and absorbs the sunlight, producing heat. Small tubes connect the collector to the tank, where the hot water is stored for consumption.Solar water heaters are systems that were made to heat water in swimming pools, Jacuzzis as well as for domestic use at home. Heated water for bathing, dish-washing, laundry and other uses is available 24/7 because solar water storage facilities are gigantic compared to conventional ones so as to facilitate use of hot water throughout the night since little or no energy is generated at night.
Home lighting systems consume a lot of energy, so home owners need to change from the mainstream light bulbs which uses between 40-120 watts to LED light bulbs which only use 20 percent energy of the mainstream bulbs.
Lastly, we should also look at one of the daily home chores – ironing. Most of the hot irons are not usable on solar energy. So the only iron that so far can be used on solar is the dry iron only.
Having done all this you have all information in your hands so the next thing you need is to determine the kind of system you need especially the solar panels. Quality matters and quality will never come cheap. Nevertheless, get quality rather than cheap ones.
Cheap solar panels are very costly in the sense that they have a very low and poor quality output.
Most of them don’t even last more than five years, no wonder why many hate solar energy – it is because you bought the wrong product!
A quality solar panel has a lifespan of about 25 to 40 years without any replacement and that’s the reason they are expensive. There are several retailers that sell quality panels like Shenzhen from China, Horizon Star Energy.
NAPS, a Finnish-based company, manufactures one of the best panels and has been in this business since the early 1980s. Most of their panels are being used all over the world to power farming, commercial and household applications.
In closing its important to note that the initial start-up costs in the home solar systems are very high but they will produce forth fruit in the process of time.
Takaendesa Denhere is a researcher and writer on renewable energy. For feedback contact him on his email: [email protected]
