Small system, no storage

[Miffedone]

Our house has a cedar shake roof with about 10 years life left ($100,000 replacement cost), so don’t want to install a large system now. I have 12 small (100w) panels “flying” off our deck which pre-heat water to the water heater (dump load, basically), and I can add another 12 to run? I’m thinking of two room A/C which are only used when the sun is out and hot (or space heaters in winter), so “instant use”, no storage. I can add another 20 or so panels but have no real use for the power unless you have suggestions. (EV someday but not now). I am loathe to install an expensive battery storage system, and wouldn’t know how to integrate it into a large home system anyway. (Home: 4,000 sq ft, sited for passive solar) Suggestions appreciated, including resource books, sites, or literature that can get me to the next level. Thanks.

[Mike90250]

There's always pole mounts

And, if you are going to cover up a nice shake roof with solar panels, just re-roof with 50 yr asphalt shingles and have the solar installer and roofer work together.

[J.P.M.]

1.) I assume you're connected to the grid but current PV is not ?

2) Ever think about a ground mount ?

3.) I also would not consider batteries, at least until you get a handle on what you want to do and know how that's accomplished.

4.) If it was me, and if I was hooked up to the grid, and my POCO had a NEM arrangement available, and depending on my budget and electrical usage, I'd get a grid tied PV system - ground mount if practical and feasible - sized to give me lowest long term cost/kWh mix of PV and POCO power, provided the LCOE of the combination was less than the LCOE of simply buying all your power from the POCO.

5.) With that roof, I hope you're not in fire country.

6.) In the meantime, a book: "Solar Power Your Home for Dummies". Getting a bit long in the tooth but still quite useful.

[Miffedone]

1.) I assume you're connected to the grid but current PV is not ?
2) Ever think about a ground mount ?
3.) I also would not consider batteries, at least until you get a handle on what you want to do and know how that's accomplished.
4.) If it was me, and if I was hooked up to the grid, and my POCO had a NEM arrangement available, and depending on my budget and electrical usage, I'd get a grid tied PV system - ground mount if practical and feasible - sized to give me lowest long term cost/kWh mix of PV and POCO power, provided the LCOE of the combination was less than the LCOE of simply buying all your power from the POCO.
5.) With that roof, I hope you're not in fire country.
6.) In the meantime, a book: "Solar Power Your Home for Dummies". Getting a bit long in the tooth but still quite useful.

1. Yes, home is grid tied, current PV is not. We live in TVA territory (Knoxville) which does not have/allow net metering. There is a substitute but it is onerous and not compelling.
2. Ground mount is how the final 20 (or so) panels would join the club.
3. Batteries will come much later, I figure.
4. No NEM, interconnect requires long contract and control to utility which, at this time, I don’t want to do. So I am building piece by piece around that without interconnecting any circuits. That is challenging, especially without storage! See *addendum.
5. Not a fire issue here. (Also not interested in scraping off the shakes in favor of asphalt. The roof is a major architectural piece of the home.)
6. I remember skimming “Dummies” a while ago but never bought it. Perhaps I should. Thanks for the thoughts/suggestions.

4* The next piece is another 10-12 panels to handle climate in an exposed, under-HVACed sunroom. Too hot in summer, too cold in winter. I’m thinking it will be a decent use of real-time production; A/C in sunny summer, ribbon heating in sunny winter. (Already have shades, window tint, etc. but they’re pretty ineffective. The sunroom is a previous owner’s add on and has just one duct where all others rooms have 2 or 3. I have duct booster fans, etc. so I’ve played out that string, too.)

[J.P.M.]

1.) I assume you're connected to the grid but current PV is not ?
2) Ever think about a ground mount ?
3.) I also would not consider batteries, at least until you get a handle on what you want to do and know how that's accomplished.
4.) If it was me, and if I was hooked up to the grid, and my POCO had a NEM arrangement available, and depending on my budget and electrical usage, I'd get a grid tied PV system - ground mount if practical and feasible - sized to give me lowest long term cost/kWh mix of PV and POCO power, provided the LCOE of the combination was less than the LCOE of simply buying all your power from the POCO.
5.) With that roof, I hope you're not in fire country.
6.) In the meantime, a book: "Solar Power Your Home for Dummies". Getting a bit long in the tooth but still quite useful.

1. Yes, home is grid tied, current PV is not. We live in TVA territory (Knoxville) which does not have/allow net metering. There is a substitute but it is onerous and not compelling.
2. Ground mount is how the final 20 (or so) panels would join the club.
3. Batteries will come much later, I figure.
4. No NEM, interconnect requires long contract and control to utility which, at this time, I don’t want to do. So I am building piece by piece around that without interconnecting any circuits. That is challenging, especially without storage! See *addendum.
5. Not a fire issue here. (Also not interested in scraping off the shakes in favor of asphalt. The roof is a major architectural piece of the home.)
6. I remember skimming “Dummies” a while ago but never bought it. Perhaps I should. Thanks for the thoughts/suggestions.

4* The next piece is another 10-12 panels to handle climate in an exposed, under-HVACed sunroom. Too hot in summer, too cold in winter. I’m thinking it will be a decent use of real-time production; A/C in sunny summer, ribbon heating in sunny winter. (Already have shades, window tint, etc. but they’re pretty ineffective. The sunroom is a previous owner’s add on and has just one duct where all others rooms have 2 or 3. I have duct booster fans, etc. so I’ve played out that string, too.)

Sunrooms such as you describe got a bad reputation for just the reasons you describe and more. Most of the problems stem from DIY'ers who don't understand the finer points of passive design and its subtleties including the need for proper air movement into/out of the space. I had a sunroom addition in Buffalo, NY that incorporated moveable interior insulated shutters for winter heat loss and external shades for summer heat gain, windows and ceiling ventilation for temp. control as well as a lot of thermal storage for temperature moderation. It was comfortable most of the time.

Most DIY designs simply use way out of balance design parameters including excess fenestration, inadequate insulation, inadequate thermal storage and inadequate air circulation with the results you describe. Include those things in a redesign and your comfort levels in the room will increase. Doing so will also increase the solar contribution of heat to the rest of the dwelling.