The Tribune

By BURLINGTON STRACHAN

Bahamas Power & Light

THE decision to install a solar system should not be taken lightly. It is a significant investment that you are going to have to live with and pay for in years to come. All solar systems are not created equal, and all installation professionals do not adhere to professional and ethical business standards. Great care is therefore required as you consider this investment.

You should first consider why you want to install a solar system. The answer to this question will impact the amount you spend, what the system can and cannot do, and what your payback period will be.

If you just want to help the planet by reducing your carbon footprint and nothing more, a simple grid-tied system will allow you to do this with the minimum level of investment. Your return on your investment would not be driving your decision, and so you would likely be happy with whatever level of return you get.

On the other hand, your desire may be to reduce your electricity costs. A simple grid-tied solar system can also do this, provided you understand a couple of crucial things:

• This type of system does not provide emergency power if the utility company supply goes down.

• Even in the day with full sunshine, if the utility goes down, these systems will typically shut down and not generate any energy as this is a built-in safety feature.

Financial Benefits

The amount of money you will save varies based on the use pattern of the system and the cost of electricity in your rate category. It is at this point that you must become familiar with a couple of simple formulas that you can use to determine the range of your savings.

The best thing you can do is consume the solar energy that you produce. That is when you get the highest value, since this offsets your base rate and your fuel charge for the energy you do not take from the grid. So, in this case:

Formula One.

Estimated Maximum Monthly Benefit =

(Base Rate + Fuel Charge) x System Size in KW X 6 (equivalent to peak sun) x 30 (days in month)

So for: Average Base Rate = $0.125

Fuel Charge = $0.105

System Size of 1kW

(0.125 + 0.105) x 1 x 6 30 = $41.3/month

So, at best, for each kW of system output (from inverter) capacity, $41.30 could potentially be saved.

The customer will obtain the minimum financial benefit if the customer sells all the energy produced by the solar system into the grid. So, in this case:

Formula Two.

Estimated Minimum Monthly Benefit =

(Fuel Charge) x System Size in KW X 6 (equivalent peak sun) x 30 (days in month)

So for: Average Base Rate = $0.125

Fuel Charge = $0.105 (feed in tariff rate)

System Size of 1kW

(0.105) x 1 x 6 x 30 = $18.90/month

Note that since there is no self-consumption in this scenario, there is no base rate benefit component.

It should also be noted that system losses, weather and other factors that would lower these benefits have not been included. So these are optimistic best-case values. Simply put, the financial benefit would fall between $18.90 and $41.30 per month for each KW of basic solar installed. However, energy losses in the solar system would likely reduce these values by about 15 percent. The table shown here summarises this financial benefit range for typical system sizes.

*These values are based on an average base rate of $0.125/kWh, $0.105/kWh Fuel Charge. Values will be affected by weather and the actual installation details.

Quality is Important

When deciding to install solar, the possible financial and other benefits must be weighed against the cost of the system being installed. The typical solar installation components will come with manufacture warranties.

• First, ensure you pick an installer that will honour these warranties and have this written into your agreement with them.

• Also, have them provide you with a warranty on their workmanship. The better the warranty, usually the better the product and support. Quality solar panels are generally warrantied for 15 to 20 years, whereas quality inverters are only for five to ten years unless extended.

• Be sure to register all your key components so that you can get the benefits of these warranties if needed.

• Read and understand your warranties. Do not just take your installer’s word as you may have to deal with equipment manufacturers directly.

Conclusion

The decision to invest in a solar energy system should not be made lightly. Research into installers, the cost versus the benefits, expected features and capabilities, the life of the installation, as well as maintenance and repair costs should all be taken into account. This investment decision could be one of the most significant ones you make, and you will likely have to live with it for the next 15 to 20 years. The right decision can leave you with an ideal installation that meets your expectations, whereas the wrong one can result in buyer’s remorse.

We hope this article will help you make a more informed decision when considering making an investment in a solar system.

NB: Burlington Strachan is director of grid solutions and support services, Bahamas Power and Light (BPL)