Imagine 22,000 Solar Photovoltaic (PV) modules on your roof capable of harvesting free sunlight to produce 6.7 MW of electrical power for the next 20-25 years.
If you visit the Mandalay Bay Convention Center in Las Vegas and ride their elevator to the top floor you can look out and not just imagine but actually see this new approach to today’s electrical power energy generation. Granted this is the Mojave Desert with plenty of sunshine, but the same solar collectors are used from Maine to Washington. Last year in cloudy Germany, there was one weekend when 50% of that country’s energy was provided by solar power illustrating they are well on their way to successfully carry out their plan for transitioning away from fossil fuel generated electricity by 2050.
Typically questions from the folks on this green energy tour included:
Q: How often do you have to wipe the desert dust off these things?
Ans: We haven’t had to clean them yet, but we planned to give them a cleaning once or twice a year if needed.
Q: Where were these solar modules made?
Ans: Arizona. By a company called Trina. (After a little research, it turns out that Trina is actually a Chinese company that has several American “distributors” including the one in Arizona.)
Q: What does NV Energy (the local utility company) think about this.
Ans: (The tour guide smiles politely as he formulates a diplomatic response). After a moment, the guide continues, “We are still friends. This solar system now generates 20% of the energy used by the combined Mandalay Bay Convention Center and Casino complex. But we have additional roof space so we are planning Phase 2 and Phase 3 that will expand the solar system. The design of Phase 2 & 3 is not complete, so we don’t know how many more modules we can add.”
Q: How are the solar modules held onto the roof?
Ans: Each module is bolted onto a rail system. Ballast (gravity) is used to hold the rail systems down on the roof. (This is similar to the solar array installation Gail & I visited on the roof of the IKEA store in Centennial, CO where no bolts are used – just ballast / weights. Using ballast eliminates the need to put holes through the rubber membrane that provides the weather seal for the flat roof.)
Q: Does each solar module have its own microinverter?
Ans: No. There are strings of solar modules and each string has an inverter.
After several more questions, we re-entered the glass enclosed elevator and glided down to the ground level to visit the Mandalay Bay recycling center where hundreds of tons of cans, bottles, paper, cardboard are recycled each year.
Mandalay Bay is trying to be more sustainable.