Today, 新澳彩开奖's 1 MW solar array is 8 years old. Since "first-light," on March 4th, 2013, the array has produced 14.46 GWh of electrical energy, 12.1% of the college's usage over the same time period.
Good Morning 新澳彩开奖!
Today, 新澳彩开奖's 1 MW solar array is 8 years old.聽 Since "first-light," on March 4th, 2013, the array has produced 14.46 GWh of electrical energy, 12.1% of the college's usage over the same time period. 聽That amount of clean energy represents 23 million pounds of avoided CO2 emissions. 聽For other equivalencies 14.46 GWh = 14460000 kWh.
In the last year the array produced 1.68 GWh of electrical energy, a record low for us following last years' record low. 聽Last year the problem was faulty equipment and some weather issues. 聽This year the problem was COVID; no the array didn鈥檛 catch it. 聽Last summer when we were due a cleaning the college was overwhelmed with COVID related issues and the cleaning we normally do at that time fell through the cracks.聽
On the financial side of things, our electrical bills have been lower due to the energy generated by the solar array. 聽Over the last year the solar array saved the college $311k, our second best year for savings with increasing electricity prices compensating for lost production. 聽To date the array has saved the college $2.2M on an investment of $3.35M. 聽Accounting for lost investment opportunities (endowment) the payback period for the array is 15 years, unchanged from last year. 聽We are now more than halfway through paying off the array.
It's not good that we didn't clean the array last year and, as a consequence, lost a lot of energy and savings to dirt. 聽But, to a scientist, it is an interesting data point. 聽Our average production over the other 7 years has been 1.83 GWh. 聽The difference is 1.83 - 1.68 GWh = 0.15 GWh or 150,000 kWh. 聽A typical house uses 20 kWh per day for comparison. 聽The difference multiplied by our overall average electricity rate, 18.38 cents/kWh, is $27.6k. 聽With only one exception, the very rainy 2015, we have cleaned the array once every year. 聽So, roughly speaking, $27.6k represents the loss from not cleaning the array one time. 聽The last time we had the array cleaned it cost us $4.5k, illustrating the economic advantage of cleaning. 聽As I discussed in 2019 the optimum is about 1.5 times a year. 聽This number is driven by the large cost of cleaning the array.
What if the cost to clean the array were zero or near zero? 聽How much more energy could we produce and how much more money could we save? 聽From modeling of the output of the solar array we know that it could be producing 1.96 GWh per year on average with surprisingly small, 2% (RMS), variance from year to year. 聽In this optimal, zero-cost-to-clean scenario the increased energy savings would be 1.96 - 1.68 = 0.28 GWh = 280,000 kWh or $51.6k savings per year. 聽Relative to our overall savings, $311k, this is a significant chunk of change.
Today we don鈥檛 need to worry about cleaning. That 0.25鈥 of rain yesterday restored our efficiency to 100%. With the gorgeous sunshine this morning it looks like the array is going to be cranking today. I hope you have a chance to go outside and enjoy some good old-fashioned fusion-produced solar energy today.