A question raised by one school Principal at the SAPA Conference was: I would like to install solar panels in my school, how much will it cost? This is not an uncommon question, even a valid one, considering the recent increased costs (over the last 10-years) of electricity in South Africa. The response given (at the conference) was unfortunately not what the Principal wanted to hear...
ARE SOLAR PANELS VIABLE IN SCHOOLS: The answer is a resounding YES...and NO!!! :)
YES - It is (now) financially viable to produce Solar Electricity at a cost less than we buy from the Municipality. However, we buy what we need and when we need it, and we pay for the electricity we consume, supplied by the Municipality.
The financial viability of a solar system is calculated on the kWh's generated, implying 100% of the energy generated is consumed. However, this will not be the case if only say 50% of the electricity generated by the solar system is consumed, as the cost per kWh would then be calculated on the kWh's consumed, greatly increasing the "system losses" of kWh's generated and not consumed.
Whilst the "school day" is well aligned with "sun-hours", we must take into consideration that the school year is approximately 200 days per year. So that, all electricity generated and not consumed after school hours, during holidays and weekends will be predominently wasted.
The more relevant question that we need to ask with regards a Solar System in schools is therefore: How efficiently can we consume the electricity generated by a solar system installed at our school?
This will necessitate a thorough understanding of the electricity consumption patterns in the school BEFORE we consider the option of a solar panels system.
As the cost of achieving efficiency is much less than that of a solar system, our initial objective must be to eliminate waste and maximise efficiency. After this has been achieved (and only after this has been achieved), we can begin to look at the viability of generating solar energy in schools.
To do this we need DATA. We need data, which will identify system waste and opportunities for efficiency, together with the consumption patterns needed to design a viable solar system.
To simply consider replacing the present inefficient electricity demand with "green energy" is counter intuitive...at best wasteful, and certainly makes no financial nor common sense...!!!
Having said all this, there are other considerations that would need to be taken into account, such as: "energy security" (the spate of recent load-sheading reignited this need); while some may argue that replacing electricity generated predominently from fossil fuel (coal) with even a wasteful renewable energy system, would bring greater environmental benefits. :)
Injecting the solar electricity generated to the Municipal grid would be the ideal solution to resolve many of the barriers detailed above, although this presently await changes in legislation.
Battery storage is also not considered, as this is presently not considered financially viable.