Our solar results - 4 months

May 15 was the completion of OUR 4th month on solar too. Our watt hour meter as of yesterday reads a surplus of 1,327 Kwh. ... or just over 11Kwh per day. I'm expecting the next month (leading up to the summer solstice) to raise the daily surplus just a tad. Now, all I need is a line on a good EV deal to burn up that daily surplus.



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Man, that's a lot of surplus. You could run Tripp's whole house with the surplus alone! I'm using about 15 kwh/day this month so you could put a pretty good dent in my core usage with that. Of course when I have to start running the old low efficiency AC in June that will change in a hurry.

 

Good job,,,,pretty cool to see that meter spin backwards,, and to show to the naysayers how well it works in the real world.

Your daily surplus would run my house for almost a month!

Icarus

 

For those of you that have the solar installed...what's your cost vs. benefit analysis. How many years to break even on the install in your particular situation?

 

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Certainly, that's the question of the hour.

I may be building a house (well, a contractor will be doing the building, I'll just be paying for it!) in about a year's time. Of course I'm considering solar as a potential option. I'm just beginning to do some research, and wondered if those who have solar would be willing to share some actual data in terms of payback.

... Brad

 

thats a lot of money

what do you do with al the water thats inbetween the roof and the solar panels... i dont see any rain water pipes.

 

For those inquiring minds,,, here is a link to a different forum,,, populated by some very smart, very experienced folks who have been there, done that in every aspect of RE power, including solar heat and hot water. PV solar, wind etc. Solar Electric Discussion Forum by Northern Arizona Wind & Sun - Powered by vBulletin

The short answer to the original question is quite complicated because of differing metering rates, time of day metering, net metering, rebates from utilities, from state and local governments, and tax credits.

What can be said,,, and if you are going to build from scratch you get a leg up,, is that the general order of things to consider are, Conservation first! For every $ spent on conservation, ~$10 will be saved on RE costs. After doing all the conservation you can think of,, the second thing to do is conserve some more. This conservation includes ground water/ground source heat pump heating and cooling, using AC for hot water heating if you live in an AC climate etc. Then consider solar hot water, passive then active solar space heat, in that order, and only then begin to consider PV solar.

If you are in the design phase, proper roof orientation/angle for PV solar can make a system much more efficient. Proper window and glazing locations can have a huge effect on heating/cooling load. Proper overhang size to shade in summer, shine in winter should be considered.

In short you can design a VERY efficient house that uses 1/2 the energy of it's next door neighbour and yet from the outside it would appear similar rather than exotic.

Good luck,

Icarus


PS We are seeing install costs of about $8-10 per watt inclusive for grid tie systems now,,not counting any incentives which can lower that by 1/2 in some cases. A typical house system might start ~2kw or so and go up.

 

Our CA home is located in an area that afforded us about 1/2 the cost in rebates. But since then I've discovered there are areas in CO that will cover over THREE FOURTHS the cost ! ! Dang. So the term 'geographics' (applied to 'payback') not only covers how much sun you get during the year ... it also covers how heafty / puny one's tax credits & cash rebates may be.

Only after our install, did I discover how VERY simple it would have been to complete our PV project as a DIY. Much of the gear is modular now ... requiring great stupidity to muck it up. There are several 'how-to' books on the subject, and the actual grid tie effort would be the only thing really necessary to get a contractor for. THAT bit of ignorance cost us about $15,000


Live & learn ... again.

Yea, OUR AC compressor is 15 years old. Around 1PM yesterday we cranked up the AC just to see what the meter would do regarding direction of travel. It went from a healthy clip running in reverse ... to a moderate clip moving forward. Ugg. Hopefully we won't get any ultra-hot days until july. The low 'E' windows last year really help too.

 

How much does your utility pay you for the surplus?

 

Say what? 11 kW-hours in one month would consumed by one 100-W light bulb on less than four hours each day.

 

ThanX for the link, and great information, Icarus! Now, it's time for some serious research!

... Brad

 

We use,, on average between 3-700 watt hours per day,, for all uses. We are off grid solar powered. We run 3-5 Cfls in the evening as needed after dark. The house needs no light during the day ever. We charge our lap tops, run the satellite internet modem, pump our water, listen to the radio/cd/satellite radio, paddle fan etc. We heat with wood, have a wood fired hot tub.

Keep in mind that we have no TV which helps a lot and our fridge is propane powered. If were to add a conventional fridge it would add about .5kw/day. We also live in a very small house that is very efficient. Gas stove that has no electrical requirement, Propane demand hot water that requires no electricity etc. No phantom loads,, we know where every watt is being consumed all the time.

The point is,,,if we lived in a conventional house, conventional sized, we would probably triple the total electrical use to ~2 kwh day,, a bit more if for the freezer. One doesn't have to live in a cave in the stone age to live well and live with great energy efficiency. Yes it comes with some minor upfront costs over "conventional" houses, but the pay off is quick and permanent. There is no reason that MOST houses couldn't live on about 1/2 the net energy they do,,,and the cost benefit would be astounding. The idea of one light fixture with 40 bulbs drives me nuts. Either we are serious about this stuff or we're not.

Icarus

 

You've got to make some rather serious changes to get down in the 2 kwh/day range if you have kids. With kids one is looking at about 1 load of laundry per day, 1 load of dishes, and one or two cooked meals (depending on time of year.) That's roughly 3 kwh/day for clothes/wash & dry with front loader and sensing dryer, our Energy Star dishwasher pulls about 1 kwh/day effective (but uses less hot water than handwashing the dishes). I'm less clear on the cooking heat, but have budgeted about 2 kwh/day. And unless you want a cramped refrigerator, 1 kwh/day is more realistic for a family fridge. Either that or one is likely to end up with a small refrigerator and a small freezer...and again end up in the 1 kwh/day range.

You can convert various things to gas, but much of this is simply load shifting from one fossil fuel to another. While we used wood as our primary heating (and some cooking) when I was a kid, a cord works out to about 5,000 kwh equivalent/cord if my calcs are correct. The advantage is that it was sustainable use where we lived.

While I've cut this home's electricity use by one half in the past year (compared to the previous owners' use, they were at the apex of complete inefficiency) I'm reaching a point of diminishing returns that require larger investments/more complex management, or considerably more daily chore labor.

 

I'm not meaning to imply that everyone can or should get down to 2kwh/day,,, and you are right, load shifting to gas, or wood is just that,, load shifting.

What I am saying however is that MOST houses have a long way to go, and there are lots of simple things that people can do that can save a ton! For example,, just changing out a fridge can save 75% over one ten years old. Unplugging the 20 year old fridge that keeps a few beers cold 24/7 can save 100% of it's cost. Waste heat air to air heat exchange, ground source or hot water heat exchange heat pumps. Yes,,, most of these things come at some up front cost,,, but the payoff is quick for our wallet,, but more importantly the payoff for the environment is huge. As I have always said,,, ad infinitum, the cheapest energy dollar is the kwh we don't have to generate.

As we say in the solar business,, the order to do things is convervation first. Every $ spent on conservation will save ~$10 in solar cost. After conservation comes more conservation,,, followed by still more conservation! Then,,, and only then does it make sense to pursue solar,,, Water heat first, followed by passive and active space heat, and only then PV solar. It doesn't make a lot of sense to put of 2kw of PV solar to feed 2000 watts of conventional bulbs,,,when the same 2kw of PV would feed ~3 times as many cfls for example. Same with air conditioning, appliances etc.

Icarus

 

i thought he said it was 11 kwh PER DAY

 

It was 11kwh/day,,

Enough top run that 100 watt light bulb for ~110 hours.

Icarus

 

I was feeling pretty smug about my plans to drop my house's monthly electricity consumption to 200 kWh/month until I read Icarus' post.

 

That's still incredibly impressive to me. I'm running about twice that right now...as long as I can keep the AC off. I've got a couple of things that really hurt (not counting the two kids): one is the Radon vacuum blower that runs 24/7 for about 10% of my base load, plus about another 13% in vampire loads that I'm working to slay one-by-one. About half of the vampires are structural: security sytem, garage door openers, smoke/CO detectors, phone, HVAC, oven, UPS's. Without some improvements in vendor hardware offerings, there is not much I can do about them. Only a couple of the remaining ones are good candidates for elimination through replacement.

I could have knocked out about 20% of my base electrical load by switching to a gas dryer when I did my recent washer/dryer upgrade. (Of course, this is really load shifting to another source rather than eliminating energy use.) I had four concerns that prompted me not to do it: 1. I had a good gas dryer about 20 years ago that dried very quickly, and I remember it running rather hot compared to electric--I was wanting something gentler. 2. The newer ignition systems are less reliable (obstinate about actually working) to prevent idiots from blowing themselves up when spilling gasoline next to their gas fired appliances. 3. It would have cost me about $500 to retrofit for gas. (Although admittedly this should have paid out quickly enough.) 4. I'm moving toward direct vent/sealed systems in the utility room so that I can further tighten the whole level--having another gas burner would have moved me in the opposite direction and therefore hurt HVAC efficiency.

My old PC's are energy hogs too...but these are items that I'll get around to as upgrades happen (of course my oldest PC is going on 9 years with original motherboard build and OS install despite many upgrades and overclocking experiments way back when...so this can take awhile.)

The other major guilty pleasures are the 8% of base load consumed by a chest freezer and wine cellar. But these pay me back in "quality of life" issues. (I did unplug my old college fridge that was serving as a beverage cooler when I bought the wine cellar.)

 

Shawn,

You are still doing better than 90% of other American households. Keep fighting those phantom loads.

Personally I would give up the garage door opener and the security system,,, but that's just me. Can you figure out how to do a wind turbine (you know the kind to vent attics, not the electric wind turbine) to vent your radon?

I don't know a lot about radon venting,, but if you have wind,, it would seem that some sort of natural draft could go a long way to pulling the air out.

Icarus