September 2022 State of the solar art and installation on a home...

oldmako

So I am toying with adding a system to my home.   There are SO many variables and opinions I thought that I'd ask here as opposed to reading endless ADS and articles written with the intention of SELLING me something.

BLUE RAVEN came by my house last night with the following offer...

TOTAL SYSTEM SIZE          -     12.045 KwDC
NUMBER OF PANELS          -     33   "Tier One"
YEARLY PRODUCTION       -     14,953   kWh
ESTIMATED  OFFSET          -     90%


TOTAL SYSTEM COST        -     $64,678
FED TAX  CREDIT (30%)     -     $19,253
STATE CREDIT  (Va.)           -     $2229

25-year, transferrable loan at 1.99 pct.
25-yr warranty on the panels and inverter.



Needless to say, I am going to get another quote or three before making any decisions.    I am 63 yrs old and retired.  The plan is to stay here indefinitely, but who really knows at this point?   

They claim that the house value increases by 4.1 pct.   They also claim that houses with solar sell FASTER.   I question that since my panels will be mounted on the front of my home.

I am certain there are a lot of questions that I need to be asking at this point.  I am just too ignorant to determine what they are.

What's right/wrong with this?  Any opinions are welcome and thank you for your time.

BB.

All the following are my personal opinions. If you have questions/see things differently--We are all here to learn.

First. I do not call GT Solar an "investment". If you have $60,000 floating around looking for someplace to go--Can be nice.

HOWEVER, get the documents from the supplier/installer... Warranty, loan paperwork, who is responsible for repairs, what happens if system does not produce expected amount (either shading, electrical issues, failing panel(s), failing GT inverter, etc.).

You may have 10-20+ year warranty, but you may have to cover labor after 5+ years (yes, will get new panel, but you pay to diagnose/labor to R&R).

Be aware--Things (in general) churn in the electronics/solar/etc. market... 5 years down the road, may not be able to find same/similar replacement panels, GT inverter, micro inverter(s) may no longer be available (same brand/model)...

In general, for electronics (all electronics) past ~5 years can be difficult to impossible have repaired/get parts. In California we have a 10 year warranty on solar purchased with CA credits... Probably most suppliers are 10 years now(?). Again check for labor/etc. costs if covered by warranty or not.

Check how your utility charges/credits for GT Solar Energy. When GT solar started 10+ years ago--The billing plans were pretty nice for the GT Solar owner (basically full credit off my bill for every 1 kWH generated--At the end of one year, have "trueup" if I generated enough or "extra power", I did not owe any money for power other than a $5-$10 per month connection fee).

Now, GT solar is very popular. And the State PUC and the Utility have been "adjusting" rate plans. They are now making peak and off peak charging into 8-9pm at night... Solar does not generate during late evening or in the dark. Solar billing is no longer (in many places)as it used to be (I can argue--Less subsidies from "regular" customers to GT solar customers--Fair or not fair?).

In California, they will only guarantee "rate plan" basics for 10 years (grandfather)--After that, who knows where things will go.

Note that standard GT Solar systems do not produce power if there is a power failure (no backup power). Storms, car hits pole, etc.... No power for you until the grid is restored.

Note there are a few GT Solar systems that can generate 1,000+ Watts in the middle of the day (i.e., you can plug your freezer into the "secure power" outlet of the GT solar system and run the freezer in the middle of a sunny day).

Personally, I don't believe that GT Solar adds the value of the home. At best, maybe a little added value... Or you may run into buyers that think the panels detract from the looks of the property, or are afraid of all the wires and panels on roof/side of home. If you got 10%+ from the $60,000--I would be very surprised (who pays off loans/leases if you move...).

If you have neighbors--What if they build an addition that blocks sun... Or trees/landscaping that grows over time (you have to hire tree trimmers, you cannot control grown on neighbors/open land).

Personally, I highly suggest going through and look at Energy Conservation first. It is almost always cheaper to conserve energy than to generate it....

• Ceiling insulation
• Energy Star rated HVAC
• Weather Stripping
• HVAC Duct insulation (i.e., piling insulation over ducts, etc.)
• Possibly looking at mini-split heat pumps (more efficient A/C vs older systems, Modern heat pumps can use 1/3 to 1/2 the amount of electricity vs resistance electric heaters even down to freezing or below).
• LED lighting
• Turning off stuff not in use (entertainment systems, desktop computers and such can take a fair amount of power if "not being used")
• etc.

For a home that has never really looked at energy conservation, it is very possible to save 25% to 50% of energy usage (gas, electricity, etc.).

Getting a Kill-a-Watt meter to measure individual appliances (refrigerator, computer, and such)... It is sometimes surprising, a microwave using 1,200 Watts for 15 minutes (1/4 hour) per day uses 300 WH per day. A desktop computer running at 150 Watts (not in "sleep") 24 hours per day can take 3,600 Watt*Hours per day... (3.6 kWH per day)

If your system is sized to produce 12 kWH or 12,000 WH per day (or 360 kWH / 360,000 WH per month)... You may be paying around $0.15 to $0.50 per kWH--California is now around $0.40 to $0.50 per month--More than Hawaii now).... Measuring your energy usage and figuring out where to spend your money...

1,200 Watt microwave---0.3 kWH per day * $0.20 per kWH = $0.06 per day
Desk Top computer "left on"---3.6 kWH per day * $0.20 per kWH = $0.72 per day

The (mythical) desktop computer (networking, router, cable modem, printer, etc.) can use 10x as much energy per day vs a microwave in random use.

Also, if you use A/C in the summer--Inefficient appliances (refrigerators, freezers, desktop computers, etc.)--Basically all of the energy they use ends up as heat (i.e., your 150 Watt computer is the same as plugging in a 150 Watt heater)--So in this case, you are paying to "heat" your home (old computer, old fridge, filament lamps, etc.) and then paying for the A/C to remove the heat from your home.

Another way of looking at whole home energy usage... Something like one of these:

https://www.theenergydetective.com/

They can measure the whole home energy usage, and you can purchase versions that let you measure major loads (electric stove, water heater, dryer, well pump, etc.)...

Other things to look at... If you have an "older roof", you may need to include the price of a new roof (array mounted over homes roof). 25 Year panel "life" and 20 year old roof--Not a good mix.

And if you have a "more difficult roof" (metal, tile, etc.)--Mounting the array standoffs and preventing/fixing leaks can be an issue...

A roofer I have used over the years--He was looking into installing GT Solar--Much of his work was fixing leaky roofs after a roof top solar array was installed (poor weather proofing around array anchors).

Also look at roof top wiring--If have little animals that like to chew/nest--The array and array wiring can attract those little guys.

There can be other issues too... Depending on local electrical codes--There are access issues for roof (so firefighters can access roof to ventilate--Walking space). And there are issues with array power cutoff (shorts, arcs on roof top, new codes can require "remote shutdown" devices or micro-inverters (one inverter per panel) vs central inverter(s) (one inverter for whole array).

You don't really need to worry about code issues (your installer should be doing this work)--However, down the road issues can cause you headaches/extra costs (replace bad panels, replaced failed micro inverter on roof X years down the road)...

Your estimated harvest is 14,953 kWH per year and covers 90% of your usage:

• 14,953 keH per year / 12 months per year = 1,246 kWH per month solar
• 1,246 kWH per month / 0.9 total home load = 1,384 kWH per month total
• 14,953 keH per year / 365 days per year = 41 kWH per day solar
  
• 41 kWH per day / 0.90 total home load = 45.5 kWH per day total

https://www.eia.gov/energyexplained/use-of-energy/electricity-use-in-homes.php

Your home, presently, uses a fair amount of electricity... If only have electricity (no natural gas), and A/C--That is not unusual... Lots to think about. But my first choice would be Conservation (measure existing energy usage) and replace energy hogs... 

-Bill

oldmako

Bill, WOW.   TONS of useful information.  I knew that my ignorance was vast, but my understanding of the depth of my ignorance was.... let's say "generous".   Many thanks.  I will pour over this when I have a bit more time and get my learn on.

You're exactly right about my (1989) house being an energy pig.  Last year I used 15,440kwh of juice.   Located in Virginia Beach I have a dual-power heat pump (elec/gas) since the HP function is worthless when it gets cold, and it does in Dec-Feb.  But the insulation is a joke.   Decent windows, but that's about it.

Many thanks for all the info.

Steve

Photowhit

I'll be 63 in a few weeks, might also consider extra based on capacity to charge an electric car in the future. Though with a 12kWh array you/they might be at a threshold of a 10kWh input to the grid and a larger array might require insurance.

Additional considerations might be for the 'climate' for Net metering in your area. Florida now has a $30 minimum bill for everyone. Some talk this disrupts the roll over credits. Also tax exempt status for solar electric systems (currently in 30 states) might be going away. I live in Missouri where at least commercial installs will likely have property taxes applied in the future.

NextEra Energy (a huge conglomeration with Florida Power and Light as 1 of over 700 subsidiaries) is behind some of the Florida $30 minimum bill basically working against home solar while also doing a lot of large solar electric 'community sized' installs. 

Coyyote

We live on a ranch in the Rockies and have off and on considered solar but really did not feel it made sense economically. However with the changes occurring in the country we have felt a need to become much more self sufficient. For example our water comes from a well with an electric pump.  If grid goes down - no water for us or livestock

We did install a propane generator but if outages continue for really long time we could run out of propane, which lately has doubled in price

All the above pushed us in the direction of a grid tied system just big enough to handle all our critical tasks. Was this a good economical decision - NO. But it was a good security decision in my opinion. 

BB.

Welcome to the forum Coyyote,

Just to be clear--Grid Tied Solar (in the traditional sense) requires a working utility (aka grid) connection. GT Solar (no battery bank, etc.) will not provide any (AC) power if the utility power fails--This is intended as a safety measure to prevent electrocuting linemen/other customers (i.e,. your GT System back feeding a 1/2 dead grid connection).

There are GT (and hybrid) Inverter systems that can provide "backup" 120/240 VAC power to a separate "protected" AC power connection--But only when the sun is up and shinning--Dark, cloudy weather, etc.--And the inverter will shutdown.

And then there are the full Hybrid (both GT and Off Grid) AC inverters that use a battery bank + options (solar charging, genset charging, grid charging) and will supply normal AC power to the home (based on inverter and battery bank capacity)...

In general, GT solar (solar=>GT inverter=>main panel)--It is the cheapest ($/kWH) solar power you can generate (probably under $0.15 per kWH). Add battery bank + solar charger + maintenance + battery replacement every ~7 years, new electronics every 10+ years, etc.)--Is probably on the order of $1.00 - $2.00+ per kWH (really depends on how you use the power)... One member here has gotten his off grid solar power down to $0.50 per kWH or so (find good deals on batteries and hardware, manage loads to use most of the generated every day)...

As soon as you add a battery bank--The costs go up. Many times, for short term outages (few days, couple weeks--Maybe a once in 10 year ice storm), a genset can be a better solution (they only burn fuel when running--In standby--Gensets don't cost much to maintain/pickle for backup power)... Off Grid Solar--Really is only cost effective if you are using its power for something like 9+ months a year.

There are lots of solar hardware options out there. You really need to define your needs (Watts and kWH per day, Utility power, backup genset, over paneling solar array to generate more energy in winter, etc.)...

The details matter in solar/electrical power systems.

-Bill

Coyyote

Howdy Bill, being new to this I don’t have all the lexicon down. Appreciate your education. The system we have is by your description 

“ And then there are the full Hybrid (both GT and Off Grid) AC inverters that use a battery bank + options (solar charging, genset charging, grid charging) and will supply normal AC power to the home (based on inverter and battery bank capacity)...”

We have no plans to sell back, but just be independent as much as possible, which is a good idea but not cheap. 

Photowhit

Coyyote said:

We live on a ranch in the Rockies and have off and on considered solar but really did not feel it made sense economically. However with the changes occurring in the country we have felt a need to become much more self sufficient. For example our water comes from a well with an electric pump.  If grid goes down - no water for us or livestock

We did install a propane generator but if outages continue for really long time we could run out of propane, which lately has doubled in price

All the above pushed us in the direction of a grid tied system just big enough to handle all our critical tasks. Was this a good economical decision - NO. But it was a good security decision in my opinion. 

I'm the guy who feels I'm about as cheap as an off grid system can be... For off grid systems, which must have a battery bank, the key is NOT having a backup generator and it's related expenses. 

My costs are roughly 30 cents a kWh, and perhaps a little cheaper, before the Income Tax Credit (ITC) of 30%. Link to system below, I really need to do a 10 year update. If the current batch of All-in-one, inverter,charge controllers prove to be reliable, I think it could be even cheaper today. I'm that cheap mostly because I use a lot of air conditioning directly off the array without the traditional 3 days of autonomy normal in design. 

It's going to be close to cost effective! or Off grid at 26 cents a KWh! - Page 2 — northernarizona-windandsun (solar-electric.com)

Heating with solar is mostly a 'non-starter' certainly where I live, perhaps in the desert southwest. I also use water heating as an opportunity load, so will use water heated on the wood stove often during the short late fall and early winter days. A gas water heater may be in my future as this is getting old at 63, but might meet your description of "critical tasks". I find many people don't understand electric, once you've lived on a minimal solar electric system(Not what I'm describing here) you turn power off when not in use. I find most grid tied friends are difficult to visit. Once a TV is turned on it stays on, room lights are also on for the day once turned on. I suspect most people who grew up when off grid solar was expensive learned good habits. 

For your system the big load would be the water pump. The new generation of All-In-One inverter/chargers might have issues with the high startup load.

Dave Angelini

Coyyote said:

Howdy Bill, being new to this I don’t have all the lexicon down. Appreciate your education. The system we have is by your description 

“ And then there are the full Hybrid (both GT and Off Grid) AC inverters that use a battery bank + options (solar charging, genset charging, grid charging) and will supply normal AC power to the home (based on inverter and battery bank capacity)...”

We have no plans to sell back, but just be independent as much as possible, which is a good idea but not cheap. 

Please explain how a grid tie without a battery helps you feel more independent? Are you AC coupling or something?

Coyyote

Yes AC Coupling and do have a battery bank. The grid is my back up so to speak if it is up. If it is down the the propane generator is back up.