Monitoring of electricity usage following the activation of the solar panels was conducted from the 10th of February to the 15th April. On the 15th of April, a new electricity meter was installed which does not allow for the direct monitoring of electricity usage on a day-to-day basis. It has still been possible to measure the benefits from assessing the electricity bills, however.

Table 1 presents a comparison of the average weekday and weekend electricity usage from before (24th October 2013 to 10th February 2014) and after (11th February 2014 to 15th April 2014) the activation of the solar panels. The data indicate that average weekday usage of electricity from the grid fell by almost 45%, and average weekend usage by almost 60%, across the two periods.

Table1: Electricity usage before and after activation of solar panels
 
Weekday Average (kWh)
Percentage Change
Weekend Average (kWh)
Percentage Change
Before activation
25.13
-44.7%
56.01
-59.7%
After activation
13.91
22.57

It is also possible to estimate the reduction in CO2 emissions that have resulted from the activation of the solar panels. Using the figures in Table 1, the average weekly electricity usage was 181.66kWh before activation, and 92.12kWh after activation. This represents a weekly average saving of 89.54kWh. Based on an estimated grid factor of 0.4898 (kgCO2/kWh), this translates into a weekly saving of 43.86 kgCO2. Extrapolating this over the course of a year would represent a saving of 2.28 tonnes CO2.

Furthermore, we can also assess the monetary value of the reduced electricity usage by looking at the electricity bills. In the three-month period from October to December 2013, before the solar panels had been activated, the average monthly bill for electricity was N$985. Following activation, the average monthly electricity bill for March to July 2014 N$429. This represents an average saving of N$556, or 56%, on the monthly electricity bill1.

Although the two periods do not provide perfect comparisons, primarily due to different potential for solar power production at different times of the year, the reduction in electricity usage and bills is striking. Over the course of a year, a simple extrapolation of the existing data indicates that approximately N$6,700 will be saved as a result of generation of solar power.

 


1The months of January and February are not included: the former because there were only estimations on the electricity bill, and the latter because the solar panels were activated halfway through the month.