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Showing posts with the label PV

Daily solar PV system output analysis

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We saw how the Tesla planned output compares to our own prediction using PVWatts. That is all theoretical. Time for a reality check...how does actual output compare to what is expected from the system?  Recall, you can extract a daily and hourly breakdown from PVWatts for the entire calender year....And, you can extract the actual system output from the Tesla app. It records about every 15 minutes. Lets see what we get: Here is my system output on Dec 9, 2020. It was about as sunny as you can get all day in the Denver area. So a best cast scenario. We made 19.3 kwh of energy that day. If you download the data into the csv file, you can get the time stamped output. It's in 24-hr format. Here I highlighted two random times: 1045m and 230pm (1430 hrs) that corrrspsond to 3.2 kw and 1.6 kw total system output. Other times are shown too. Now, we can take out our PVWatts files. In my case for East and South: - pull the values for the same date and time -add them t

Solar journey: Design and predicting annual production. Part 2

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Tesla's plan estimated annual production at 6622 kwh. I have not designed a system before nor had one. It is close to what other quotes called out. Aside from waiting a  year to see, is there a way to run the numbers your self? The answer is yes. The National Renewable Energy Lab (NREL) has a user friendly site an calculator to help you do this. Its called PVWatts. Link below: https://pvwatts.nrel.gov/ PVWatts requires your location so it can use its database to determine the seasonal average solar radiation (accounting for weather). Once you enter.your location, it is on to.entering the PV  system properties If you have all of your panels in one direction, this easy. In my case, the panels are split between East and South....so I have to enter each half separately, then add them together to get the total  system estimate. PVWatts provides typical default numbers. Here is what I entered using my Southern string as an example: -Half system size=2.78 kw (7 pan

Solar journey...the plan

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Timeline: 2 days after order: Solar layout sent for approval by me. I did not approve it right away. I wondered if I could customize before signing off on it. Timeline: several days after order: Tried texting the given # and emailing the address given to discuss layout and customizing beyond 4kw basic system....no response after a few days so called a bunch of times to reach the PM (project manager). Once I got ahold of him, he was very pleasant  he did say the design could be customized and the cost per watt would not change. They would  look at upsizing to the max allowed (120%) of historical usage....back to design team (updates and communication via text is handy with them) Timeline: ~1-2 weeks after order: Since the first design was so rapid after ordering, I thought redesign would be just as fast. After a few days...nothing. Tried calls to the Project Manager 3 times a day....mailbox was full the first few days so had to keep calling.  (it was expected based on the reviews I rea

Solar journey....Energysage vs Tesla

Energysage quotes vs Tesla The prices quoted from Energysage were all very close. Competitive amongst themselves. The average quote was $3.12/W. For a 4 kw system in 2020 (26% tax credit): Energysage $3.12 x 4kw=$12,480-$3,245(26% credit)= $9,235 or $2.31/W Tesla $1.49 x 4kw= $5,960 #Solar #Tesla #energysage A difference of $3,275. Would you pay 55% more than you need to? 5-10% maybe.... Breakeven in 16 years or 10 years? 10 for me. Considering Tesla?  Use this referral link to get started and get a $100 award from Tesla after activation. https://ts.la/zach38035 #solar #energysage #tesla

Solar panel journey.....on to Tesla

Too busy to shop around? Energysage is a central market place that can pull many quotes from nearby installers and it provides lots of information about going solar.   My quotes from Energysage (Front Range, Colorado) #1 $ 3.10/  watt #2 $3.05/ watt #3 $3.19/watt #4 $3.15/ watt (all prices before tax credit) Several of the follow up calls were aggressive, pushy....salesman.   Some were laid back. I knew what DIY costs were amd Tesla. So these were way too expensive...payback too long. Most played dumb when asked about Tesla pricing. Tesla  was $1.49/watt (after tax credit).  Thats all inclusive (hardware, installation, permitting). How can you not know your competition pricing? One salesman acknowledged and played the local, customer service angle.  Tesla does have quite a bit more negative reviews out there mixed in with some postives.....and poor customer service is a big complaint.... But the price difference is too compelling.... I placed an order with Tesla Online in lat

Solar Panel journey...

Well any major purchase requires due diligence....I solicited several quotes from installers. Energysage can do this for you. https://www.energysage.com/ Keep in mind your system is typically limited by your historical consumption (120%). I do not know if this varies by location. So if you are a miser, you can't just plop in a 12-20kw system....plan ahead and burn some juice for a few months  (mine bitcoin?). If you are handy, consider DIY. I went back and forth with wholesale solar which is now Unbound. Its very doable. The  savings are good and can halve payback time. https://unboundsolar.com/ They were helpful. Never said anything about the 120% rule though. Having a  30ft 40 degree (10/12) pitch stopped me though. google-site-verification:googlebddf70ee9885a3b8.html