kiev wrote:Some questions after seeing Tim's photos,
So in an angled versus "flat" PV installation, might the flat version capture some energy during the morning and afternoon while the angled version is in shadow?
Once the Sun comes up to the front side then the angled version dominates at Noon with a higher peak maximum output due to the pointing angle, but on average thru the day a flat version might be acceptable even though it creates a lower peak but longer duration output?
Kenny, need to do the math to properly answer this question - happily, all solar contractors have the gadgetry and software to do just that, quickly.
When I first installed my ground-mounted solar they had complete freedom to orient the panels in any direction and any angle and they supposedly optimized it for the best average for my latitude. The system was optimized to maximize energy harvesting.
However, there is one more variable to consider: Time Of Use (TOU) pricing
, with the utility finally realizing the effect of the Duck Curve (look it up) and now really sticking it to the consumer.
To show you how extreme it has now become, my summer TOU rates are -
Partial Peak 37.8¢/kWh
Where Peak time is now 3pm to 8pm, Partial Peak is noon-3pm and 8pm to 10pm.
Six years ago I went to expand my system and had three differently-angled roofs I could use: SE, NW, and S. I had a big debate with the contractor as he was attempting to optimize energy harvesting and I was attempting to optimize $$ harvesting. We both agreed that S was best but that was my garage and I didn't want to add much more weight as it is a huge open span with massive trusses and already has a concrete tile roof. Whereas I agreed that SE was best for total energy harvesting, NW would utilize the very high-value late afternoon sun and I was convinced the utility would be shifting the TOU Peak window. I finally solved it by asking that my house be a science experiment: six panels on SE, six panels on NW, and five panels on S. Turns out we were both wrong about the South-facing panels as we didn't take the chimney shading into account. The contractor was right that SE was best for total energy harvesting but I turned out to be right from the $$ harvesting standpoint as in the last five years the utility has shifted the Peak times (which used to be noon - 6pm) into the early evening.
I'm happy to say that, despite having an all-electric house and a whole bunch of electric cars I haven't had to pay for my electricity in the last 15 years, although the monthly meter fee has gone up from $5/month to $10/month, and even that gets partially refunded.
When I first put in my solar (high priced in 2006) I had calculated it would amortize in 17 years. Reality is that it amortized in seven
, because the rates have been going up massively (to think they were once 9¢/kWh), with electric car operating cost (vs. ICE) thrown into the amortization equation, as well as the energy-reductions I've done.
Meanwhile, the utility needs to recover $$ because of all the lawsuits that drove it into bankruptcy for causing many of those California wildfires. Thankfully, clean energy Community Choice Aggregation has come into play which now actually pays me for my electricity generation so I no longer have to be content with having my huge $$ surplus be zero'd out each year by the utility.
Sorry for digressing...