Working our way to payback

Well, it's been a while since I've posted in this thread....for the most part because things have been uneventful.  The system continues to work extremely well and it's making 100% of our hot water between mid March and mid October.  In the winter, it needs very little electric backup to hit the 120 degrees we have set as our temp.  To date we've received three SREC payments from SOLSYSTEMS since we contracted with them last year.  Between the electricity offset and SRECs, this system should fully pay back in 6 years.

Total Cost Total Payback Initial Cost  $9,386.00  $9,386.00  $    -   State Solar Grant  $1,500.00  $7,886.00  $1,500.00 Federal Tax Rebate  $2,815.80  $5,070.20  $4,315.80 2011 Offset  $332.32  $4,737.88  $4,648.12 SREC Payment Aug 2012  $180.00  $4,557.88  $4,828.12 SREC Payment Dec 2012  $180.00  $4,377.88  $5,008.12 2012 Offset  $335.47  $4,042.41  $5,343.59 SREC Payment June 2013  $180.00  $3,862.41  $5,523.59

Early Stagnation

Wow, warm weather and sunshine have topped the 150gal tank off with hot water all the way. Collector return line hit 160F and the system stagnated for the rest of the day. :)

March Update

It's been a while, so I figured I'd give an update on how the system is working. To date, it's generated over 2500kWh of energy to heat our water and offset over $350 in electric costs. Our old water heater was also less efficient, so the electric bill is actually down more than that. Over the winter we also added more blown in insulation in the attic and done a few other small things like go to T-8 lamps in our kitchen main light. We've started tracking the savings on the Share MyGreenQuest website: http://share.mygreenquest.com/kaptainkriz
Overall, we're down nearly 42% on consumption in no small part because of the solar system. Maryland now allows the generation of SRECs for certified solar systems utilizing the OG-300 Estimated Annual Output (kWh). We are in the process of registering with SOLSYSTEMS http://www.solsystemscompany.com/ to sell our output quarterly. Our OG-300 rating is 2933.00kWh for the area and the Equivalent Nameplate Capacity is 2.444 (kW). We anticipate earning an additional $527 a year for the next few years from these SRECs.

11 Days of Shade

Well, I'm beginning to think I need to build an Ark!! We've had weeks of rain and finally our hot water use has exceeded system generation capacity. So, I kicked on the electric backup for an hour to bring things back up to temp. Hopefully the sun comes out soon so I don't need to do that again. Back in April I turned off the backup to see how much hot water the system could generate. It's made 100% of our hot water (plus some) all summer long, so I left it off. Based on the graphs I've been keeping, I believe that we'll need the backup turned on full time in early November when the days get shorter and sun low in the sky. BTW, that hour or so ate up 7kWh to get things back up to temp. Glad we're not running that every day!

Commissioning Day and Rebate

Been a while since I posted, but we finally got our final inspection done on June 10 and commissioning/completion paperwork submitted. It's now July 19th and we got our MD Solar Grant check in the mail!! Yay! Next phase is to figure out how to register the system for SREC generation. I believe the system needs to be SRCC certified to qualify. SES has been working on that testing for their system design for a while now and anticipates publication/acceptance this year. This means we'll be able to qualify for the sale of SRECs in MD, further reducing our breakeven timeline and allowing the state power generation entities to get credit for our reduced grid usage.

One Month of Solar

Usually our electric meter gets read on the 14th, which would be today. Since last month, I've been keeping track of daily electric use by reading our meter on the side of the house. It's interesting how aware you become of electric use when you do that.....an extra load of laundry, dishes, etc.... it all adds up. What I'm trying to see is if the effects of the solar hot water system can be seen in the bill... I think they can, and it's more than I expected. Of course there are other factors like weather that play in..but averages speak volumes. I have plotted in excel, every electric bill for this house over the last 10 years (January 2000). For the 28 days spanning 14 February to 14 March the bill has averaged 1537kWh with a low of 1247kWh last year and the runner up of 1290kWh in 2000 when we 1st moved in. This month, the bill was only 1035kWh! The lowest bill EVER for the period since we moved in. That is roughly 17% down from the low and 32.6% down from average.

The days are still pretty short and the sun pretty low in the sky...the system is not supplying all our hot water under these conditions and will only get better throughout the spring and summer. I'm looking forward to seeing if the trend continues.

As for calibration, the control unit is clearly under calculating the kWh generated...by how much I'm not sure. I believe this is because I have the incorrect flow rate programmed into it. As I take more data I'll see if I can predict and back into the correct calibraction factor...for now, it is good enough to tell a good day from a bad day and act as a diagnostic.

System Cost

So, inquiring minds want to know...what did the system cost?

There are a number of ways of looking at that.....so I will just give the simple answer:

$9386.00 installed (out of packet expense)
Federal 30% Tax credit: $2815.80 (received during next tax cycle)
Maryland Grant 20% capped at $1500.00 (received later this year)
Needed a new water heater anyway and was looking at the GeoSpring ($1482.94)

Effective cost $3587.26
7 year payback

The complicated answer includes inflation and electric rate increase. (5.5 year payback)
The deceptive answer also includes your tax rate and treats the expense as an investment (I don't buy into this one <5yrs).