iDRY Vacuum Kilns


Grid Tie Solar

Started by Jstier, May 05, 2021, 10:59:09 AM

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I just saw this section of the Forum and figured I'd throw out any help that I could offer to anyone with questions regarding Grid Tie Solar.

I am currently running a 16,000W Grid tie system. I have half roof mounted and the other half ground mounts. I did all the work myself and had about 14k invested. Our local electric company does a buyback program that changes rates through out the year. Summer months we usually are getting paid/credits from the electric company and winter time our bill is usually around 190-200. 

My ROI was about 5 years. We have a large cabin and everything is electric in it, so this really helped out with it all. I looked into batteries but with the price of them and lifespan it made more sense to just invest more money into the panels and get paid back more. Actually pretty excited to get my Kiln up and running and make some more money off free power.

 I ran cryptocurrency mining farm out of my basement for awhile and tried to make some extra money with the solar as well, but have since sold off all my miners. Its amazing all the hobbies you can get into with extra electricity :) 


Great story, once solar farms really get cranking the almost free cost of power generation is going to open up a lot of neat ideas.  As you said, batteries are  the real holdup.  As battery production increases over the next 10 years that will open up even more ideas.  Solar is so cheap right now it is heading to near 0, saw bids from some GW size projects and the bids are just ....crazy low.  

Liking Walnut


I am getting ready to pull the trigger on a grid-tied system. I bought a stand alone "solar generator" to back up the essentials but as I am on the main 3 phase line serving town my outages are infrequent and short lived so a large battery back or whole house system really isn't justified. I also learned during the massive ice storm here in 2009 that the government can and will commandeer all the fuel supply so you are more or less going to be reduced to running only the most essential items anyway should the "big one hit".

Even having the work done turn-key my calculations come out to saving me $170 per month on a project that's going to cost me $25,000 after the 30% tax credit.

I have no illusions that this is going to save the planet. What it will do is pay me $170 a month on a 25K investment and that is at today's electric rates. My last month's bill, in addition to the base energy charge, has a fuel adjustment of .01397, an Environmental surcharge of 11.99% , a school tax of 3.0% and a sales tax 0f 6.0% tacked on for good measure. One doesn't have to be Nostradamus to know where the rates are headed going forward.


I have had a grid tied solar system for over 20 years and slowly added capacity to the point where I produce more than I need on a yearly basis and it goes into a surplus account that I use to run a minisplit for heating. The big thing before considering grid tie is if your state and more important your utility is "solar friendly". In some cases, states allow utilities to be "solar unfriendly" where in the worst case, they prevent you from hooking up to the grid or steal any excess power. In my case I am on a "grandfathered" rate plan that is no longer available to new customers that is hard to beat, I basically use the utility as a battery with no surcharges. New installations in my state, NH, are still okay but it allows the utility to buy back surplus power at a big discount to what its selling power for and turns it into a cash credit. Most programs are set up that once you connect the system the rate plan is locked in for the life of the system, but some states make changes retroactively.  I have not looked into the details, but California reportedly has made a big negative change for new solar installations basically forcing a battery installation to shift power usage. 

So before going grid tie, its best to design around the utility rate plan. It likely in the future that the plans will be set up to encourage a battery installation. The battery allows the user to shift when they use power over the course of day.  Some utilities will pay the users to install a battery with the proviso that the utility can "borrow" the output to deal with short term grid issues. This is great place to start to look for incentives and it has a built in solar calculator Database of State Incentives for Renewables & Efficiency┬« - DSIRE

Whatever you do avoid creative financing solar, the salesman can be very convincing and work on commission. They make lots of promises but they are long gone as soon as they get a commission check. At a minimum have a lawyer familiar with solar review the contract. Be aware that many plans us backdoor methods of putting a lien on the property and in most cases the landowner will have to pay a high priced ransom to sell their own land or con some new buyer into taking over a bad deal. There are very few folks happy with leased or creatively financed systems a few years out. So if you cant pay cash to own a system, its best to wait and save up. Prices year after year are dropping for systems and most expectations are they will continue to do so.

If you are considering solar a somewhat dated but still very useful book to buy used on Amazon is Solar Power Your Home for Dummies. It basically will get you to understand the language. Solar is not that complicated, I designed and installed three of my systems myself. The problem is it has got its own rules and terms so a salesman can overwhelm you with BS and make you think he is doing you a favor by translating it (but his translation is biased towards his commission).

Lots of hobbyists are building completely off grid systems, unlike grid tied solar which is almost "plug and play", off grid is not, and what may be state of the art today may be unsupported and orphaned a year from now.     


Franklin buncher and skidder
JD Processor
Woodmizer LT Super 70 and LT35 sawmill, KD250 kiln, BMS 250 sharpener and setter
Riehl Edger
Woodmaster 725 and 4000 planner and moulder
Enough cows to ensure there is no spare time.
White Oak Meadows


4+" ice. All the cell towers were down. Roads not only impassable but illegal to travel on for non government types. ATM networks were non-functioning. No city water. Unless it was a mom and pop store, you couldn't buy a thing even if you were within walking distance. Under a declared state of emergency the government appropriated all the fuel from the distributors. Only the national guard, hospitals, and official government shelters could obtain fuel. Even the stores with generators couldn't process checks or credit cards and could get no new supplies. If you didn't have it on hand the day the storm hit; you were doing without. It loosened some after the first week but some were over a month before the power was restored.

Unusual amount of ice but compared to other possible events it sure gives one pause to think just how totally dependent we have become on the whims of the powers that be. Covid was a good reminder of just how much control we have already ceded and where you stand when your internet, cell phone, and credit card all quit functioning.

East ky logging

That was a terrible ice storm. We was out of electric for over three weeks here. Took me almost two days to clear out the road me and a couple more families live on and it's just a mile and a half.
I've got a few gas wells on my farm and had about everything hooked up on gas so we had heat hot water and able to cook and had a gas log truck that had two full tanks of gas to siphon out to run the generator but a lot of people had a rough time.
They who can give up essential liberty to obtain a little temporary safety deserve neither liberty or safety- Benjamin Franklin


In how many states do the 'abandoned/ orphan gas well' capper charities operate in ?  (China burned 4.5 billion metric tonnes of coal in 2022)

Are there any US versions of these (chinese?) 5 in one systems.
battery units stackable to 48kWh
Solar inverter(solar panel to home battery?), EV DC charger(charging your EV from the home battery), Power Conversion system, Battery Pack, EMS - energy management system. Said to have vehicle to home and vehicle to grid modes.

Powerwall 3 is due 2024. Cybertruck is said to have electrical system differences to previous 'light vehicle' Teslas.

maple flats

I have a dual system. I have 4820 watts grid tie only and 1480 watts battery back up/gride tie.
I just removed the grid tie connection on my 1480 watt portion. With the world situation I just wanted to have a separate back up system. On grid tie, if the grid goes down the solar by necessity (worker safety) shuts down. If there was an EMP either caused by solar flares or by an adversary, the grid would be shut down, if the latter it would be years before the grid would be back up.
I have my off grid system protected I hope, enough that I'd still have some power. I hope to never find out, but I'm trying , if I've done everything right.
Yes, batteries are expensive, especially if mistakes are made. I had such a mistake. But first my story from where it started before I went grid tied in 2008. I had my 1480 watts all off grid and had 8 Trojan 240 AH 6V lead acid batteries, in series, for a 48V battery bank.
Then in 2012 I decided to go grid tied, and I added 22 more panels 220 watts each and put them on a Fronious 5000 watt inverter. They were grid tied. My 1480 watts remained off grid  a year or maybe 2 and I decided to also couple that to the grid. My inverter an XW6048 was designed to do either, fully off grid or grid tied. I stayed grid tied until about a week ago on that portion. Along the way, after the Trojan batteries needed replacing in 2019 after 11 years service which is good, I read about some way better batteries and I bought 16 LiFePo4 (lithium iron phosphate) batteries, ($2500 cost) 100 AH to make a 48V bank. I set it up in my unheated sugarhouse. I read that they needed to either be protected from freezing or needed a heat source. These batteries can not be charged when they are frozen. So I got a 65 watt heat pad and built an insulated enclosure for the batteries out of 1" rigid foam. The batteries were fully enclosed. That type of batteries require what is called a battery management system (BMS). a BMS has a fine wire that goes to each battery so the BMS keeps the charge of the batteries always ballanced. I programmed as in the instructions to shut off charging at 34F, 2 degrees above freezing. Then we had a 3 day snow storm and 2 things happened. Snow covered the panels ,the temps fell into the 20's and the BMS failed to shut off the charge. I discovered this on day 4. The batteries were at 17.3V, not 48V as designed, and the BMS had tried to charge them. They were ruined, could not be resurrected. I got a fancy pulse charger that could  be set up to pulse charge at any voltage from .1V to 6.0V as suggested by someone on the web, they thought it might save the batteries, but I tried a bunch of settings but nothing worked, the $2500 worth of batteries were toast. I only got about 7 months use. A long shot, from what had been prodicted to be 25-30 years. I then bought 4 12V AGM batteries, 200AH for $1300. They are now working and hooked up, doing well. The reason I changed from the original flooded lead acid (FLA) btteries to Absorbed Glass mat (AGM) batteries is only because they require no maintainance. FLA batteries need to get an electrolite check up every month, in use the electrolite "boils off hydrogen" and water needs to be added to bring the level up to where it should be H2O. 2 parts H to 1 part O. At 77 years af age I didn't want to need to follow the level for 11 years more (my first battery bank lasted 11 years 3 months) that would have been when I was 89 yrs old, having had 2 birthdays in the 11 yrs 3 months. Also I knew of no one who would handle the task. Thus I went AGM. If used as much as I did on the first battery bank these should last 10+ years, if the grid goes down it likely would fail 2-4 years sooner because they would be drawn down farther and more often.
Any wats, batteries are expensive. If any of you go lithium iron phosphate is suggest they only be kept in a heated space, unless new technology allows them to be charged at lower temperatures or unless you live where it never freezes.
logging small time for years but just learning how,  2012 36 HP Mahindra tractor, 3point log arch, 8000# class excavator, lifts 2500# and sets logs on mill precisely where needed, Woodland Mills HM130Max , maple syrup a hobby that consumes my time. looking to learn blacksmithing.

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