IMPORTANT NOTICE

Many people have purchased generators as a way of beating the current energy crisis.  One alternative that people have considered is solar energy which is noiseless, non-polluting and is derived from a source that is free of charge, i.e sunlight.  Not enough public education has been done on the merits of solar energy.

A common perception about solar energy is that it is expensive, but this is wrong.  For an investment that will last you thirty years or more, solar systems are a very good value.  There is almost no running cost and the replacement costs of some equipment such as batteries only occurs once every few years. Also you get the advantages of low running cost and a system that is modular and expandable.  You can start with a small system and add on to it at your convenience.  Solar is an energy solution that goes far beyond the present energy crisis.  It is a solution that will keep saving you money for many years to come.

When is it best to go solar and when should one settle for a generator?  What are some of the important things you should consider in deciding for one over the other?  It all depends on your short term and long term needs.

Is there enough solar energy in Nigeria to have the system working adequately all year round?
Yes.  Cloud cover varies from place to place, but even under indirect light solar panels still produce appreciable power.  It is also important to keep panels free of dust, particularly in the Harmattan season.

What are the fixed and running costs? Especially in relation to a generator/electricity inverter etc
Generators provide an easy but ultimately expensive standby power source.  They are readily deployed and can supply power indefinitely as long as fuel is available.  The initial cost of a diesel or petrol generating set is usually lower than a solar system of the same capacity.  Whilst a solar system may cost more to start with compared to a generator, it costs very little to run.  In fact the only running cost is that of replacing batteries every few years.  Because the energy is stored, you can use as little or as much as you want at the same efficient rate.  However, being more conservative (by using low energy bulbs) lets you run your system for a longer period without recharging.

The solar  system pays off against the generator after about three years.  If you plan to use standby power continuously for three years or more, you're better off with a solar system.

In home based solar system some of the key components are:
solar panels:  used to generate enough power for the household by placing them on a rooftop or similar open space.  Panels can last up to 25 years

Batteries:   used to store the energy produced and ensure that electricity is available both day and night. Batteries can be changed/upgraded every couple of years

Charge controller: used to control the charge level of the battery; usually a one time purchase

Inverter: converts the battery's energy to 240 volts AC so that standard household appliances such as televisions, fridges, and fans can be used. Usually a one time purchase.

There is almost no running cost for a solar system and the replacement costs of some equipment such as batteries only occurs once every few years. Thus a solar system's running costs are virtually nil, while the costs pile up for running  a even small1.2 kVA generator for 12 hours a day;

Comparing solar with generators watt-for-watt is not correct because you may need a much smaller capacity solar system to run the same load.  Generally, generators are designed to handle a worst-case load.  You determine the maximum load by adding the various loads in your house, and then you select a generator that is sized above that maximum.  With solar, on the other hand, you need to know the characteristics of that load in addition to the maximum.

For example, the maximum power a fridge will draw occurs momentarily when the compressor motor starts (you can hear it start every few minutes).  The power drawn is less when the compressor is running steadily, and the fridge draws very little power when the compressor is not running.  If you were selecting a generator for your fridge, you should select one that will be able to run the maximum load of the fridge.  If you were running the same fridge on solar, it would be equally important to design for the total energy Charge controller consumed by the fridge.

What kind of maintenance is needed for a Solar system?
There is virtually no maintenance required except for occasional cleaning of the panel surface to keep it free of dust and dirt, and regular battery checks. 

What kind of appliances can it power – especially the heavy duty ones like air-conditioners, fridges and the like.
You can take full advantage of solar's strengths by using it as an energy source for specific applications.  Generally, solar is best suited for lighting and electronic equipment such  fridge, freezer, TV, lights, stereo, computer, a fax/printer. Solar is less suited for powering air conditioners.  You can still take advantage of solar technology by combining your generator with solar and PHCN in a hybrid system.  For people with air conditioners and other high-consumption equipment, you might be better off using a generator for those because the cost of a solar system system to run those appliances may be prohibitive.  However, everyone should consider using solar system for lighting.  There is no point wasting fuel and firing up your generator just to keep lights running.

An energy expert can help you determine which appliances in your home are best for solar and which others can be run by other means.

How many years of service can I expect from a solar energy system before replacement?
Most systems can last well over 20 years.  Quality panels have a 20-year warranty. Batteries last for 2-5 years, depending on the type.  Other components usually carry a one year warranty.

Can I use a diesel or petrol generator with my Solar  system?
Yes.  In addition to standalone solar systems, you could opt for any of these combinations:  solar/PHCN, solar/generator, or solar/generator/PHCN.  Any of these options can be installed into your existing distribution system and configured to switch easily from one power source to another.

Your Solar system can drastically reduce the amount of money you would spend on a generator.  With a hybrid system you can use the generator for heavy loads or emergencies, while your Solar system provides power and saves you money every day.

Can the system switch automatically to solar when there is a power cut?
A standby solar system can be installed into the electrical distribution of your home or office, and can be fitted with an automatic or manual changeover switch. 

Is a Solar system expandable?
In most cases solar systems can be expanded simply by adding more panels or more batteries, depending on whether you need more generating capacity or storage capacity, respectively.

What about security;.  How secure are the panels?
Solar panels are mounted with deep concrete bolts, and would be difficult to remove by unauthorized people.  In addition, the panel has far less value on its own without the battery, controller, and inverter which are indoors.

I need a system to power a fridge, freezer, TV, lights, stereo, computer, and a fax machine. Not all the equipment will be on all the time, but the fridge and some lights must be on.  How much will it cost?
Solar Power for such a system would cost from 2 million naira depending on how long your appliances are on, how efficient they are, and how "independent" of PHCN you want to be.  A Solar energy consultant can make a detailed assessment of your needs.

Could electricity from mains be used to help speed up the battery-charging process?
Yes, it is possible to have a standby system designed which charges from mains when it is available and from solar at all other times.  This helps reduce the overall cost of the solar system.

If the solar panels are to be mounted on the roof of the house, how much space is required?
Panel sizes vary; however allow for about 3 feet by 1-1/2 feet per panel.  The installation space should be clear of obstruction (shadows of buildings and trees) throughout the day.  Rooftops are usually good, and flat concrete roofs are the most stable for flat mounts.  It is also possible to have a tubular wall mount for buildings with tile or slate roofs, or a pole mount for ground installation.

Until next week....enjoy the sunshine
By Chi Akinlotan
Today.gspltd.solar@gmail.com