Solar in Connecticut – A Year in Review


It has been a while since I have posted on my solar install, but I wanted to wait until the year was over to be able to give a full accounting. Any posts earlier woudl not reallyhave added much new information.

First things first – what does my system look like, this is what was installed (from the Tesla documentation):

  • Quantity: 24 Panels
  • System Size: 7.56 kW
  • Est. Annual Production: 6959 kWh
  • One Powerwall
  • Location: Newtown in Connecticut – I have a house, the panels are installed on the roof of the house

2020 Production and Usage:

My solar Production and Home utilization for 2020

Totals:

  • Solar energy Produced (kWh) 7053
  • Home usage ( kWh): 8664

So, the estimate that Tesla gave me in the beginning of the project was very close – production is determined by so many factors that can’t really all be taken into consideration but I am heartened to see that I am pretty much right where I hoped to be.

The sizing of the system was done to be able to cover most of my energy needs over the year – you can see I overproduce in the May/June and Aug/Sep which helps – more on that below:

Note: there is a branch or two on a tree that will be going down to get some more late day hours of production for next year …

Impact on Electricity Bill:

Just keep one thing in mind – the period for my electricity bill and the monthly stats for Tesla do not align – Eversource bills from the 23rd of each month to the 22nd of the next and the Tesla stats I created are based on a full monthly period (1st – 28th/30th/31st).

2019 Bills2020 BillsSavings
$189.20$52.26-$136.94
$159.43$78.87-$80.56
$143.34$10.93-$132.41
$160.05$24.61-$135.44
$139.45$9.58-$129.87
$147.33$9.62-$137.71
$183.20$9.62-$173.58
$166.75$9.62-$157.13
$146.12$9.62-$136.50
$121.47$9.62-$111.85
$127.96$60.16-$67.80
$182.25$140.69-$41.56
$1,866.55$425.20-$1,441.35
Compare 2019 to 2020 Eversource Bills

This table only shows part of the story though – what I really need to compare was what I would have payed Eversource for the electricity that my house used vs what I actually had to pay Eversource for. That is really what shows me the savings for 2020 energy that I did not have to buy from Eversource:

From Grid (kWh)To Grid (kWh)Grid ResultskWh SavedEversource Sav
543.1025.80517.30306.500 $65.49
489.70266.60223.10414.500 $88.56
503.00441.8061.20634.000 $135.46
474.60404.7069.90635.900 $135.87
378.50633.60-255.10912.500 $194.96
296.50424.10-127.60865.800 $184.99
475.30378.8096.50794.200 $194.32
373.80354.5019.30702.900 $171.99
286.40304.70-18.30641.000 $156.84
381.20158.90222.30414.800 $ 101.49
487.30119.80367.50322.300 $78.86
741.9028.80713.10200.600 $ 49.08
5431.303542.101889.206845.00$1557.91

The numbers above make some assumptions in terms of rates and also that I am counting a surplus production (= I exported more to the grid than I consumed) as a saving. Overall I would have had to pay $1557 more for electricity if I did not have solar production. That is significant in terms of saving.

Connected Solutions

If you have read my posting about joining the Connected Solutions program you will know that it is a bit opaque in terms of what your actual earnings can be. Basically it allows the electricity supplier to tap your Powerwall when it needs energy during high usage times and you get paid for that in the end of the year.

So, the results were actually quite encouraging – Eversource tapped my battery 30 times over the summer and in December Tesla sent me a check for $451. Tesla coordinates the program for all of it’s deployed batteries and takes some money off the top of what Eversource pays out – but that is a known issue from the start. The only thing I don’t like about this program is that there is no place in either your Tesla app or the Tesla portal that gives an update of the details – you have no way to verify how many events happen, how much energy was actually taken and see how the program progresses over the year- all you get is a an email that a check was sent and letter with the check that tells you what it is for – that is it.

Since Tesla is obviously crunching numbers to send you money at the end of the year, I can’t see that it would be that hard to add that information to the the app or the portal on the web – I really dislike black holes when it comes to programs like this. Tesla – are you listening? 🙂 Give me data!

Final Financials:

Keep in mind – the periods for billing & payment do not match the strict monthly stats by Tesla so the numbers do not add up 100%. The difference is not so large that it would have made me change my calculations to match the billing cycle … that just seemed too much detail for no real gain.

ItemRate
Estimated 2020 Electic Bill $ 1,866.00
  
Actual Eversource Bills $    425.20
Solar Array Rent $ 1,000.00
  
Total Savings 2020: $    440.80
Electric Production and Solar Array Savings

This is just for the electricity production – I saved more than $440 last year and once electricity rates go up again (as they will eventually) I assume I will have higher savings.

I do not include the costs for the Powerwall in this equation since it is not related to electric production but is rather a back-up system only. Also, I overpay my monthly payments (I financed the battery) so I can pay it off earlier and that would further throw off the picture.

The Powerwall did come in handy during the August 2020 storm that left us without grid power for a week – I had more than 190hrs of backup time and we were never actually out of power during that time since we had solar and the battery and the weather during the grid outage was sunny and we never really had a problem – I also still have my backup generator that I keep as the backup to the backup for times when solar production might be low or non-existent. Keep in mind – unless you have a battery, in times of a grid outage your solar array will shut down and be unavailable. By law, a solar array can only run when there is an active grid connection – unless the system includes a battery.

What do I like what do I not like?

The technology is good – you set it and forget it, it just works. I only had one event in the summer during the power outage where I had to physically shut down my solar charger as it was not charging the battery. That was the one and only time and it took my only 5 minutes to take care of it.

The one thing I am not enamored with is the communications black hole that is Tesla as a company and how slow things are overall. The order in 2019 eventually went through but it was slooooooow. Just as I was about to cancel it I received the notification that Tesla was ready to schedule an install date.

Last year in August I ordered a second Powerwall … an order I eventually cancelled in mid December as there was absolutely no movement on it (no matter how many calls I had) and I personally don’t like having to run after companies asking them to please take my money.

From what I gather, demand in California is sucking up all the oxygen in the system and New England is the unloved, redheaded stepchild. People I know did get their full systems ordered and installed during that same period in this area which left me to conclude that Tesla probably really likes new installs as those look great on paper, but existing customers don’t make the company shine in the eyes of stock analysts so we don’t get much love – at this point in time. I think that basically the demand is so large that Tesla is picking and choosing where to use their capacity where it makes most sense for their business and an order of a second Powerwall in Connecticut just does not feature high on the list of things to get done. Hopefully that will change over time but for that to actually then translate into a more stable business long term, Tesla will really have to put allot of work into customer service and communications. Currently those two things are so poor that I have a hard time suggesting Tesla to anyone at this time – no matter how much less expensive they have priced themselves compared to the competition. This will hopefully change in the future – good customer service is what makes companies have longevity and – pun intended – it is not rocket science.

Solar in CT – Can I Now Make Money Using My Powerwall?


Thought I’d share this right away – I just received this email below a few minutes ago from Tesla. This is the kind of stuff I had been waiting for – the next generation of the modern grid here distributed battery storage is tied together into a large virtual unit and used to aid the grid in time of surging electricity need. Whereas this is not a totally new program for Tesla, apparently it is new in the northeast – or at least I had not heard that it was available for my utility until now.

Vehicle-to-Grid is a technology that is already in use in some countries (Japan being the first one to come to mind) and tying in home battery solutions just makes sense.

This is obviously a program by Tesla where they play the role of the virtual power supplier towards the local electric utility. Tesla does have experience in these things on a large scale and they have access and control to all of the devices they have deployed anyway. standard devices, standard software and standard installation – makes for a great oportunity.

Here is a link to their FAQ they sent. To me this sounds really interesting – the possibility of this is one of the (granted minor) reasons why I chose Tesla and wanted a Powerwall to begin with. The ability to earn extra cash will be interesting – though I will have to review what an analysis of the numbers tell me – how does this compare to me being able to “bank” overproduction of electricity with my utility and reduce my overall power bill that way? And, my utility also pays out any net-gains of my overproduction to me in cash at the end of Summer. I will have to analyze that and see which solution makes more sense for me once I start seeing numbers from Tesla. Frankly, their FAQ is not really detailed when it comes to the nitty-gritty in terms of what kind of $ per kWh they are talking about. It is is lower than what I pay to and get reimbursed for by my utility it might not be worth it to me. Any electricity that was sent via this program to the grid/I need to charge up my battery is electricity that I am not “banking”. Well, the numbers will show me.

Overall – a positive way forward for the grid and solar power/battery owners in New England in my mind!