Benefits of a Solar PV System
Typically a residential system will generate the most power during the day when household consumption is not at the maximum. Without the ability to export surplus power the only options are to reduce the size of the PV system so that excess energy is minimised but this also reduces the usable energy or to store the energy until needed.
Hot water heating is a very cost effective option which with a correctly sized PV system could provide the best return on investment. A large battery solution may add significantly to the cost and would have a long financial payback time at current electricity prices. The use of a time switch on a washing machine and/or dishwasher can help to maximise the use of generated energy during the sunshine hours.
Many electricity users in South Africa, especially industrial, pay a very high tariff when they use higher amounts of electricity than normal during peak times.
Some residential users are on tariffs which are higher during peak times of the day 17:00 – 19:00 or 06:00 – 09:00 for example, or for more energy usage at any time above a certain threshold, e.g. 600kWh per month.
In these cases a PV system may be used to limit the amount of higher cost electricity consumed by storing energy during the hours of sunlight and releasing it during the high cost periods.
This may require additional timing controls to limit the time of usage of stored energy to these higher charge periods. The type and size of the battery is essential to any grid-backup or enhanced self-consumption system with many factors to take into account.
It is easy to see that South Africa could benefit from Solar PV.
Minimizing Photovoltaic Systems Cost
Fluctuation in oil prices has fuelled the demand for alternative sources of energy. One of the cheapest sources of energy is the sun. A photovoltaic system converts rays of the sun into electricity by making use of an array of solar cells and a DC to AC power converter.
The electricity created can be used directly for lighting and other applications or can be stored by batteries.
What makes the photovoltaic systems cost affordable is the fact that the sun has infinite renewability. Unlike other sources of energy such as oil and hydro whose availability varies with time and climate, we have no evidence whatsoever that the sun will one day stop shining.
Once installed the photovoltaic (PV) system has little or no maintenance therefore making it affordable to maintain in the long run.
It is however important to seek expert advice before ordering/installing a PV system. Power savings should be realized as soon as possible. For instance, the country or state you live in could determine photovoltaic systems cost.
Some states have deliberately passed legislation to encourage the use of solar energy. Such incentives include solar loans, tax rebates; solar renewable energy credits (SRECs) and Power Purchase agreements.
Once one has made the decision to go solar however it is imperative to note that there are many options to ensure that photovoltaic systems cost is kept to a minimum.
One option to drive photovoltaic systems cost down is buying in bulk where you could form a group of people interested in solar PVs and take advantage of economies of scale.
As soon as you have the photovoltaic systems in place you must monitor it for optimal performance. It should be noted that photovoltaic system costs savings are achieved by usage over a long time.
Practices to derive savings include sun tracking whereby the PV panels are placed in areas of highest sunlight and at correct angles. The panels could also be cooled so that performance may not be degraded.
The solar cells may also be protected from severe environmental conditions by encapsulation in a tempered glass cover.
Finally, to prove that benefits accrued from installing PV solar outweigh photovoltaic systems costs, it is assumed that all install costs for PV and mains electricity are equal.
The benefits would come from the fact that the monthly fee paid for a unit of electricity is eliminated when one decides to go solar. This single fact, more than any other would sway the argument in favor of solar any day and any time.