“Honestly, I don’t believe any of the numbers in the story. It indicates $300k is 8% of their use”
You are correct that the 8% seems to be an error. But the same paragraph lists minimum and peak uses that appear realistic.
“And, frankly, after reading stories on multiple solar projects, one thing is ALWAYS true - they over-project how much energy they will produce.”
Predicting the output of an experimental power tower like Ivanpah of which there is no other quite like it in the world is not like predicting a standard PV installation of which 100 BILLION watts have been installed.
The project costs should include the fence. Borrowed costs of money are standard to calculate into the project.
“And, these are the type that move with the sun to gain better efficiency “
I don’t know where you get that. The picture shows fixed frame installation.
The inverters typically have a ten year warranty sometimes extendable for a small fee. The cost of an inverter replacement on an already installed system is VERY small compared to the cost of the system.
You are needlessly second guessing an industry with a hundred billion watts of installation history.
I’m not just talking about Ivanpah. I have yet to read about a large scale solar installation that produces what is predicted.
And I guarantee the cost of the fence is not included in the project. It will come ‘later’...which means its another pot of money. I am involved in construction projects and see monkey business with the funding all the time. A 7 ft fence (opaque) on a scale large enough to surround this is a large line item all by itself.
Less than 10 miles from this site, I was involved with a large industrial client that wanted to show its green credentials off, by doing a solar field just like this one. The numbers didn’t pan out, so we didn’t do it.
Some back of the envelope calculations:
- This project is 2,629 panels, 3’ x 6’...so the total area is 47,322 sf.
- The amount of solar energy available is around 100 watts per square foot - or 4,732,200 watts or 4,732 kw.
- The best panels are around 20% efficient...so the panels convert 947 kw into electricity.
So lets back-calculate the $300k savings in the article (neglecting conversion losses). I know power is 12 cents per kwh here (and that’s to me as a consumer, a big user like the VA probably pays a discounted rate), so the panels must produce 2.5 million kwh to achieve that savings.
So, the panels would be producing energy for 2,639 hours each year. And this is why I don’t believe any numbers put out by solar advocates...ever. Its all exaggeration. Nobody in their right mind believes we get 2,639 hours of bright sunshine each year. Even solar advocates say its only around 5 hours per day...and only when the sun is shining. We get 150 sunny days or 750 hours available using that model.
So how did they arrive at their cost savings? Same way environmentalists always do - they assign a dollar value to ‘carbon’....and then the gate is wide open to exaggeration.
If the VA hospital really wanted to save money on energy, I could have helped them. I could have replaced their fluorescent bulbs with lower wattage bulbs that produce better light, with a return on investment of around 1.5 years. Or we could switch out the fixtures to LED and greatly increase the quality of light with a 5 year ROI. And in all likelihood, we could get an ROI less than 9 years on window coatings or new HVAC equipment or a reflective roof coating. Now every one of the items I’ve listed not only gets a return earlier, it also increases to comfort inside the hospital - something these solar panels don’t do.
Again, there is a reason private businesses do indeed replace HVAC equipment and coat their roofs bright....but don’t install solar. The market never lies.