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Solar Power Monitoring and Billing through SolarCity
After experiencing some growing pains with my SolarCity installation, I’m happy to say that I’ve been up and running since February 23rd of 2015 and ready to share my experiences with how the system is monitored and billed.
Savings
The savings on your electricity bill begin immediately after installation of your SolarCity system, and affects both the supply and delivery portions of your bill.
Savings can be pretty dramatic depending on the size of the system and, obviously, how much sunshine your region experiences. The following utility bill is a great example of how I was able to reduce my energy dependence from the grid by over 90%.
However, despite the reduction in energy needs from my utility company, the cost is not directly proportional to the amount of energy used. Here’s why.
Billing
Having such a drastic reduction in kWh needed from the grid actually comes with a price. Almost everyone who signs up with SolarCity opts-in to a Power Purchase Agreement (PPA) which means you pay nothing upfront (for the gear, install etc.), but you pay SolarCity for every kWh their system generates. That rate can be variable or fixed. I pay a fixed rate of $0.1420 per kWh generated for 20 years. That may sound high to you but considering my local electricity rate is $0.2470, I’m saving 43% per kWh.
It takes SolarCity some time to get up and running with their billing system. For me it took them 3 months to send me the first bill and because of that I received a hefty bill (thankfully late winter months) for all 3 months in one shot. After that, the bills arrive monthly (note that SolarCity requires EFT/Autopay to be set up).
The bills are simple and only state the amount of kWh generated, the rate you pay, and the total amount owed.
SolarCity collects data generated through their system via a standard internet connection, which they also use for billing purposes. On the first (large/3 month) bill I received, I noticed a difference of 10% (additional cost for me) between the billed amount and the amount the system had reported being generated so I naturally brought this to their attention. The customer service folks that I spoke with weren’t of much help and just told me to read each the meters at the beginning and end of each month if I truly want an accurate reading of how things get billed. So, that’s what I did.
Since inception I’ve saved $320 (over roughly 3 months) or about 42% off what I would have paid National Grid. And the system cost me nothing to install (I actually got a $1,000 Tesla-owner check from them).
They also have an estimated cost savings on the front page when you log in but it’s totally incorrect:
The mistake they made here is that they’re assuming your electricity rate doesn’t change over time. My electricity rate rose significantly after I signed up for SolarCity and because of that I’m getting a larger savings than what they’re reporting.
Monitoring
Monitoring happens online through MySolarCity.com. The interface is geared more towards new referrals than for actual owners of their system. The section I use most often is the Power Guide.
Power Guide gives an hour by hour break out of your energy generation along with the weather pattern for that day (ie. how much daylight, cloud coverage …). Hovering over each colored bar will show you the energy generated per inverter. The data can be downloaded in a CSV format and then imported into Numbers or Excel for your own post processing.
If you have multiple inverters, the CSV data for the day is a bit of a pain to analyze since it also includes the energy generated every 15 minutes per inverter.
Power Guide also includes a summary for the year.
The platform also provides a view of your energy generation as it happens in real-time which updates continuously.
Having this features allows you to watch the sun rise and set as viewed through the perspective of your panels which is kind of fun.
It’s not totally accurate as I’ll see data from certain days which look completely off.
API – Not
I’ve set up automated tweets for detection of Tesla Superchargers in real-time and decided to the same by sharing my SolarCity data through my home-grown program that fetches the data from Power Guide and then tweeting it.
It would be really nice if SolarCity decided to create a simple REST API that would allow owners to fetch their data.
Summary
SolarCity makes a lot of sense when it comes to cost savings and they’re able to provide this with no upfront cost to the owner. One needs to analyze the effective savings based on the cost incurred when generating energy through the SolarCity system versus your electricity cost, and then decide if the savings is worth the hassle. I’d recommend filling out their contact form and sign up for a consultation to get started.
The billing and monitoring side of SolarCity could definitely use some improvement, and hopefully this will improve over time as the business continues to grow.
I hope this post and series has been helpful. Let me know if you have any questions or thoughts in the comments below.
Although the two vehicles are built for completely different use cases, Tesla utilized engineering expertise while developing both the Cybercab and Semi to build a thermal architecture that would fit both vehicles. Of course, with some slight revisions.
The development was noted by Lars Moravy and Dan Priestley last week at Tesla’s Semi Handover event in Sparks, Nevada, where the company showed off its dedicated production facility for the Class 8 truck.
🚨 Tesla designed the integrated thermal systems for Cybercab and Semi at the same time as the vehicles were both in development
Tesla wanted to build one thermal system that worked with both vehicles, apart from small modifications.
Semi and Cybercab share parts 🤯 pic.twitter.com/KmzSsUbrcg
— TESLARATI (@Teslarati) September 25, 2026
Tesla’s decision to develop one thermal architecture for both the Cybercab and Semi is one of the more revealing engineering choices in the company’s 2026 lineup:
“We designed it at the same time we designed the Cybercab and we said okay we’re going to take our most efficient vehicle and our biggest vehicle and we’re going to take one thermal system and make it work for both.”
Core parts, meaning the compressor, pumps, and heat exchangers, are shared, with only modest changes to cooling-loop sizing and a larger radiator on the truck. The result, they said, is a compressor and thermal stack already proven across millions of miles, delivering “reliability from day one.”
Priestley also highlighted a practical payoff of the indirect design:
“There’s no AC lines, there’s no refrigerant lines…It comes from the factory fully charged, sealed with refrigerant, and it just exchanges coolant. It doesn’t actually run refrigerant up to the front of the vehicle.”
This eliminates potentially leak-prone plumbing that would otherwise require hands-on service, reducing overall uptime and potentially cutting into business margins. The megamanifold runs cabin HVAC and every powertrain heating and cooling loop at once, recapturing waste heat from motors and the battery instead of dumping it the way a diesel engine does.
The approach is just the latest chapter in a continuing story of stretching thermal solutions across wildly different vehicles. Model Y’s Octovalve evolved into the Super Manifold used on Cybertruck, and later Model S/X refreshes. Cybercab then introduced Supermanifold V3, which Tesla says is 80 percent automated to build and 38 percent more efficient than typical automotive thermal systems.
This thermal system is also shared with Cybercab – one thermal system for both our most efficient vehicle & our biggest vehicle
— Tesla Semi (@tesla_semi) September 25, 2026
Tesla has done the same with the 4680 cells, both being utilized in the Cybertruck and Semi, and with heat-pump compressors that Priestley noted were already common across the passenger-car fleet.
Concurrent development of crucial vehicle elements buys scale and reliability that a truck-only thermal system could not match. High-volume passenger car parts are cheaper and more accessible, which can give fleets a sealed, low-maintenance loop of operation from their first day of operation.
For owners and operators, that translates into less energy spent on cabin heat in the colder months, fewer refrigerant-related repairs, and a thermal architecture already stress-tested at passenger-car volumes before the first high-volume Semi left the lines in Nevada.
Tesla CEO Elon Musk certainly tipped off some details of the Tesla Roadster event with a broadening of information regarding the company’s decision to delay the unveiling for two weeks.
For years, people have speculated about what the Roadster will be capable of. While there have been plenty of things said about what it *could* do, we have not seen or been told by Tesla what it will actually be capable of.
However, over the past few days, Tesla’s weather updates have truly pushed the speculation into Plaid Mode, basically all but confirming the car will have some sort of aerial capability — whether that would be hovering or fully flying remains to be seen — but it definitely seems that it will be able to leave the ground intentionally.
“Because this event can only be held outdoors…”
Tesla posted on Monday that it would delay the Roadster event until October 15, and it indicated that it had to do this because the event “can only be held outdoors.”
With the potential SpaceX collaboration to develop cold-gas thrusters that will help the vehicle go airborne, doing this indoors is probably not a safe, or even plausible, possibility.
Roadster event update
We’ve been tracking the weather closely with local meteorologists, but given the severe conditions predicted & because this event can only be held outdoors, we’ve made the difficult decision to reschedule.
New date is October 15. Additional details to…
— Tesla (@Tesla) September 28, 2026
FAA Airspace Restriction
The FAA gave Tesla a Temporary Flight Restriction (TFR) for 10,000 feet above ground level, much higher than the typical 2,000-foot restrictions that are usually placed at SpaceX’s McGregor, Texas site.
Tesla Roadster event requires restricted airspace, and the FAA obliges
Some have said that this massive increase is due to Tesla’s need to restrict unauthorized drone use for spying on the event.
Elon Admits High Winds
“Due to high winds, the new Roadster demo is postponed by 2 weeks,” Musk said in a post on X yesterday.
Due to high winds, the new Roadster demo is postponed by 2 weeks https://t.co/dV3ojDh1iT
— Elon Musk (@elonmusk) September 30, 2026
A reply reading, “What’s strong wind got to do with a car demo with four grounded wheels?” was directly below Musk’s post, satirically and sarcastically probing for more details.
All signs are pointing toward an aerial demonstration for the Roadster.
Tesla has secured $30 billion in fresh credit lines from Citibank and Wells Fargo in an effort to scale its biggest current projects.
Tesla agreed to a $20 billion three-year delayed-draw term loan facility from Citibank, it announced on Tuesday. Additionally, it signed a five-year, $8 billion revolving credit facility and a $2 billion, 364-day term credit facility with Wells Fargo.
In a filing with the Securities and Exchange Commission (SEC), that it “may draw” from the $20 billion delayed-draw term “from time to time” and “no more than ten times during the 18 months following the closing date.” This loan matures on September 29, 2029.
The five-year revolving facility from Wells Fargo will also be accessed by Tesla “from time to time,” and will become due and payable on September 29, 2031. Tesla can request two separate one-year extensions.
On the $2 billion, 364-day revolving loan, it becomes due and payable on September 28, 2027. Tesla can also increase its additional commitments to an additional $4 billion across the Revolving Facilities. This would increase the total facilities to $14 billion. Tesla said it does not plan to utilize any of these loans in 2026.
Tesla plans to utilize the money to help prop up its ambitions to scale its biggest products, each of which is either in early launch phases or still in development. Of course, we’re talking about Cybercab and Semi, which have launched, and Optimus, which is still under heavy development and working toward initial release.
All three Tesla products have one thing in common: they’ve all required Tesla to build new manufacturing lines for them.
For the Semi, Tesla built a brand new factory in Sparks, Nevada, adjacent to the Tesla Gigafactory. For Optimus, Tesla sunset Model S and X production at the Fremont Factory, which brought an end to the two flagship models, thus creating manufacturing space for the humanoid robot. Finally, Cybercab is being built at Gigafactory Texas and officially entered production earlier this year.
The cash will help Tesla bolster its finances for the continuing development of these products. Tesla said that it forecasts its CapEx to be over $25 billion, up from just over $8.5 billion last year. These loans surely help with that spending.
Tesla Cybercab and Semi have more in common than you might think
Elon Musk weather update tips Tesla Roadster speculation into Plaid Mode
