Starting from scratch

Telco · August 2007

Hello, new member here. I'm looking at build a new house in 2 years, and want to go all alternative on energy for the place. The place will be built for high efficiency, and I'll be replacing all appliances, ect, so I'm not sure what I'll need for power yet. In light of that, I'd like to use my current use for a planning number, about 35 KW hours on average. I'll probably not need anywhere near this amount of electricity per day, but I do need a planning number to begin with. 35 KWH is what I average right now according to my power company's guesstimate program, and the monthly expected bill shown on the program is about what I use in power in the summer with a family of 4. When the house goes up it'll be a family of 2, with a much more efficient HVAC system, appliances, better insulation, ect. I will be adding more computing load though. Sadly I'm at work so I can't get at a power bill for better information. This number is also an average for summertime use, with the AC on all the time. Can't shut down during the day without giving the cat heat stroke.

Being as I live in the Tulsa area, and I am planning to buy about 5 acres for my gentleman's farm, I can look at both solar and wind for power generation. Danged wind almost never stops out here.

So the question is, what would I need to build a system from scratch to generate 35KWH per day year round? I'd also want about a week's worth of backup capacity included in this. Combo of wind and solar is OK, just need an idea of what controller could handle this, do load balancing and conditioning on the batteries to extend battery life and handle the load, best way to distribute, ect. Think of this as designing a fantasy system, with an eye to keeping costs down. I'll net a hefty profit off the house I'm in so I'll have some cash to play with, but if at all possible I'd like to not have to get a mortgage on the next one. Most likely I'll have to get a mortgage, would be great if it was tiny. I really doubt my power usage will be this much, one of my biggest problems is they put the laundry room in the middle of the house, so the dryer exhaust pipe wound up being so long I had to install an aux inline fan to help the dryer push the crap out. Not to mention the air conditioner and gas heater aren't able to manage keeping the place temperate since they seem to be sized for a house with no cathedral ceilings.

Thanks in advance. I know this is a completely newbie question, but while I've read a lot on how it all works, I've not found a lot that says "to make this you need that, that, and that, and this over here is a good idea, watch out for that one."

icarus · August 2007

Re: Starting from scratch

Telco wrote: »

Hello, new member here. I'm looking at build a new house in 2 years, and want to go all alternative on energy for the place. The place will be built for high efficiency, and I'll be replacing all appliances, ect, so I'm not sure what I'll need for power yet. In light of that, I'd like to use my current use for a planning number, about 35 KW hours on average. I'll probably not need anywhere near this amount of electricity per day, but I do need a planning number to begin with. 35 KWH is what I average right now according to my power company's guesstimate program, and the monthly expected bill shown on the program is about what I use in power in the summer with a family of 4. When the house goes up it'll be a family of 2, with a much more efficient HVAC system, appliances, better insulation, ect. I will be adding more computing load though. Sadly I'm at work so I can't get at a power bill for better information. This number is also an average for summertime use, with the AC on all the time. Can't shut down during the day without giving the cat heat stroke.

Being as I live in the Tulsa area, and I am planning to buy about 5 acres for my gentleman's farm, I can look at both solar and wind for power generation. Danged wind almost never stops out here.

So the question is, what would I need to build a system from scratch to generate 35KWH per day year round? I'd also want about a week's worth of backup capacity included in this. Combo of wind and solar is OK, just need an idea of what controller could handle this, do load balancing and conditioning on the batteries to extend battery life and handle the load, best way to distribute, ect. Think of this as designing a fantasy system, with an eye to keeping costs down. I'll net a hefty profit off the house I'm in so I'll have some cash to play with, but if at all possible I'd like to not have to get a mortgage on the next one. Most likely I'll have to get a mortgage, would be great if it was tiny. I really doubt my power usage will be this much, one of my biggest problems is they put the laundry room in the middle of the house, so the dryer exhaust pipe wound up being so long I had to install an aux inline fan to help the dryer push the crap out. Not to mention the air conditioner and gas heater aren't able to manage keeping the place temperate since they seem to be sized for a house with no cathedral ceilings.

Thanks in advance. I know this is a completely newbie question, but while I've read a lot on how it all works, I've not found a lot that says "to make this you need that, that, and that, and this over here is a good idea, watch out for that one."

First thought,,As to the seveal days of back up. Consider the idea of a generator for the backup. A back up is the most expensive part of any system. A generator capable of 35kwh is fairly cheap compared to that many batteries. (a battery bank of 45kwh/for several days would be huge!)

Also look everywhere to ruduce the load, cfls, swamp cooler, good design with shading etc. Also, in your climate, solar water heat. With the tax incentives you should be able to design from the ground up with a system whose net added cost would approach zero. Remember that any larger upfront cost, will quickly be recouped through energy savings. Besides, those who can afford to, should lead. It is the right thing to do. We drive a Prius not to save money, but to save the world one gallon (52.5mpg) at a time.

Congratulations,

Icarus

mike95490 · August 2007

Re: Starting from scratch

For power backup, you will need to have a sub-panel for your "critical loads" Fridge, well pump, some lighting circuits, garage door opener, TV & Radio. When grid is down, you are in "hunker down mode" and can'd afford all the luxuries.
My situation, in Los Angeles, is I have a 4.5KW array, and a monthly consumption of about 28KWH. In summer months, I spin the meter backwards a little bit, and in winter, I can't keep up. (shorter days) . I'm guessing with your added loads (Air Conditioning, Furnace blower, cat cooler etc...) you may need at least a 5KW solar array. Any chance of getting a little weather station set up at your "farm" and actually record wind speeds - that will be telling. If you have good wind, that *can* put out more power in gusty weather, than solar. You will likely end up with some sort of dual system.
What are local laws on wind generators, some areas have banned them because of noise & ugly factor.
I agree with earlier poster, have a few hours of battery life for your "critical" loads, and then run a generator to make up the difference. A 6 or 8 hour battery bank won't break the bank, but one sized for your full house, for days, will need it's own structure.
Use under ground wireing, so Ice Storms don't rip all your wires down, and solar mounts that will take your ice.
Keep us posted. Mike

BB. · August 2007

Re: Starting from scratch

You did not state if you have reasonably priced grid power available or not... Generally, you best bet is Grid Tied power with a little battery/wind/sun for emergency backup--and a generator that can power your A/C loads.

The reasons... First, Grid Tie costs you about 5-10% energy loss... Adding batteries and inverters--you now have an additional 10-20% battery loss and and additional 15-20% inverter loss--so just adding off-grid capabilities, you would have to size the array 1/80%*1/80% or 56% larger Solar/Wind array (56% more money for panels, wiring, mounts, charge controllers, etc.) just to make up for the losses of storage battery/inverter usage...

Normally, you would only go full off grid power if the lines are too far from your home to economically install them.

Using the Grid as you storage battery for the 360+ days a year you have power, and using the generator for the 4 days you don't have power, is much more cost effective--assuming that Grid Tied power and net metering (of some sort) is allowed by your utility.

Just a SWAG, assume that full off grid power would cost you over $1.00 per kWhr (assuming 25 year life of components, and changing batteries every 6-10 years)--vs ~$0.25 per kWh for grid tied solar power (assuming no rebates are available).

That 35kWhrs per day would cost you somewhere between $260 (Grid Tied SWAG) to $1,050 per month (full off grid solar SWAG).

Not trying scare you off with really high guesstimates for solar costs--depending on your system requirements, if you do some of the work yourself, have a good source for parts--these values can be +/-25% very easily.

But knowing the estimated costs for power--would you do something differently? Like take an old chest freezer and cut a cat door in it so the cat can have $10-$50 a month A/C vs cooling the entire home (semi joking). Bury the home against a hillside, shading, insulation, few south/west facing windows, etc...

The numbers to support a 1,000 kWhr per month using wind/sun/batteries is not a small or inexpensive source of power.

You probably have more sun than I... My 3.5 kW panels (3.0 kW grid tied system south of San Francisco CA), actually generates more power than I use--but I have no A/C and added a bunch of skylights for ventilation and daylight use over the kids' desks (as well as insulation in what was a 1930's wood frame home w/o any insulation, CLF's, energy efficient appliances, turn off phantom loads, keep on the kids to turn off lights, etc.). Also, I have natural gas for stove/hot water/heating/dryer...

Also, remember with Grid Tie and 1 Year Net Metering (I also have time of use power metering--more expensive during the day in summer, less expensive other times), I can store up to "one years" worth of credits and debits in my power use... So, while in the winter I generate less power than I use--I make it up in the summer by generating several times what I use in a month.... With batteries, you have 1-3 days of storage--use more or generate more than 1-3 days--that energy is (usually) lost forever (you can use the extra power to pump water to a large tank/holding pond etc. again depending on your needs...).

Does any of this help give you more ideas of how you would like to proceed?

-Bill

icarus · August 2007

Re: Starting from scratch

In your figuring, don't forget to figure in the value/cost of such things as tax credits, utility rebate' gid power over time.

As others have said, if you factor in time of day metering etc, the payoffs can be had in as little as seven years. Another, albiet more difficult number to factor in is the increase in resale/equity a good solar installation gives you. I have no real numbers, but $20,000 for a system seems expensive. $30k more for a prooven net zero grid bill annually might seem cheap for a buyer.

In these day's of crazy inflation of Real estate value added can only be a plus.

Icarus

niel · August 2007

Re: Starting from scratch

"I know this is a completely newbie question, but while I've read a lot on how it all works, I've not found a lot that says "to make this you need that, that, and that, and this over here is a good idea, watch out for that one."

actually, much of what you are complaining about that you say isn't addressed is answered on the forum. the trouble with solar and wind is that even with the same exact equipment being run by the same re products, it will vary as one may be sufficient and the other not for many reasons. the time of use comes into play as you know, but how much solar or wind energy actually is present can even vary by even less than 50ft seperating those 2 places. add to that all of the other variables out there like different locations and times of the year or differing appliances, solar equipment, etc. and because of all of that you just can't come up with something very exacting to apply to all in all cases. newbies must read up on things and learn. this is not something as simple as your utility use where they manage the production and you turn things on and off at will without knowledge or care except when the bills come you complain. this is 99.9999% of everybody in this country that fits that catagory of appliance operators. (that terminology is more familiar by those in amateur radio to criticize and insult unknowledgable radio operators) on the bright side, most here show they are above that critism by their interest to know.:D

Telco · August 2007

Re: Starting from scratch

Thanks for the responses.

My main reason for asking what people would do is kinda like fantasy football. "If I could start from scratch, what would I do? What systems would I use?" I find it valuable to get such input to use as a starting point, and someone might have a good idea that I've not seen before.

So far as the land, I've not even bought it yet. That's how early in the stages my plan is. The land will be north of Tulsa OK, within 30 miles, so Tulsa's light and wind numbers are a good starting point.

Currently I have inefficient appliances in an inefficient house, except I do use CFLs in all fixtures. In the next house, all new high efficiency appliances will be used, and I'm hoping that LED lighting fixtures will be available so I can go all LED. I do plan on having a backup generator, but would rather it not be needed unless I can't get energy generated for a couple of days. The idea here is to have free power at all times, not power I have to pay for, with the definition of bought power being power supplied by buying fuel. The cost of a larger system will be no problem since I'll have a hefty profit off my current house, to make for a huge down payment on the house I have built. With any luck my mortgage will be less than 100K when it's all said and done. Only having to "buy" my power 3-4 days per year will make the mortgage that much better.

I want to avoid having to heat with any fuel, but if necessary will have a LPG tank installed. If I have to go this way, that gas will be used for the emergency generator, and perhaps the clothes dryer. But even with that, I don't see any reason why I wouldn't be able to make the whole house all PV/wind.

Innovations I wish to include in my house are:

-LED lighting and sun tubes for lighting

-Individual wire runs to each electrical socket, with the electrical socket controlled by its own switch to allow me to turn power on and off at the wall as needed. This means no power strip needed for the TV, computer, ect.

-Computer control over the HVAC system, if I can afford it, to monitor each room and manage ceiling fans, vent controls and heat pump to maximum efficiency (this one is a pipe dream, unless my numbers come up:D).

-Whole-house attic fan, makes for a comfortable house when it's 60 to 90 degrees outside.

-Two foot thick walls with heavy insulation, triple paned windows.

-All wiring run inside 2 inch conduits, with computer wiring and electrical wiring run in individual conduits. All wiring will run to a central wiring closet, with fish line in all conduits to allow quick, easy wiring replacement when needed. No wireless networking, and no worries about being able to tap into a line when needed in any room.

-Kitchen stove vent and bathroom vents will take air directly outside. None of that cheap recirculating crap like my current house has. Along with this, laundry room will be against an outside wall to allow direct venting of the dryer. Existing house has a 70ft run for the dryer outlet, required 3-4 dryer runs to get clothes almost dry. Installed an inline booster, now it takes 1 to 1.5 runs through the dryer to get clothes bone-dry.

What I actually do go with in the end will be determined by how efficient the stuff I'm looking at is, initial cost vs long term benefit, ect. I'm pretty sure I can get my power consumption down to a quarter of what it is now, maybe to 20 percent of what it is now, just by getting rid of the inefficient appliances and moving into an R40 wall/R50 roof insulated house. If I can get it down even less than that, I'm there.

So, what would you include in your "fantasy house" when building for efficiency? And, realizing that this may not be everyone's ideal setup, what solar panels, controllers, ect would you use? Once again, just looking for a starting point, as the way I research things it helps if I get a push. In the meantime, I'll poke around the site and see what I can turn up. Thanks.

niel · August 2007

Re: Starting from scratch

i'd be a liar if i told you i never dreamed of that scenario, but there are too many variables that are suitable to me. i would have lots of pvs and a wind genny with a sizable agm battery bank for sure. which ones i'd go with are redundant as many have similarities. pvs i originally thought i'd go with i now am not sure of due to the warranty being cutback on as i believe many seem to be going similarly backward that way except kyocera.
as to the kitchen, my thoughts on that would be to be able to isolate it because of the excess heat it could produce in the summer and an obvious one of fire protection. it may not be able to be totally isolatable, but i think you get the general feel of what i'm saying about it.
dryer vent goes 70ft to the outside is a huge home. downsize the area to reduce your heating/cooling needs. when venting there is a product that can do a heat exchange with the outside cold air in the winter that we had discussed many years ago. i believe brock was the one that pointed it out and we haven't heard much from him lately so i hope he'll chime in here on this subject.

Roderick · August 2007

Re: Starting from scratch

I've had a fantasy of building a tiny house on a lava land lot on the big island of Hawaii. But there's one thing you can do in Oklahoma that I couldn't do - dig down to where the ground is cooler. Maybe if you had a deep basement to live in, the A/C bill wouldn't be so high.

I don't know the particulars of your cat, but I thought they were originally desert animals from Egypt. As long as it has enough water, I think an outdoor cat will figure out on its own what to do in 100-degree weather. At our house in Honolulu, the humans were uncomfortable long before the cats.

Telco · August 2007

Re: Starting from scratch

Heh heh, he's an old cat who has lived in a climate controlled environment his whole life. Likely he won't live to see the new house. His brother (same litter) died January of this year and he's showing some of the same signs his brother did before death. If he's not around anymore, the house can stay warmer in summer and cooler in winter during the working day.

On the 70ft dryer hose, yes and no. The house I'm in now is 1750 sq ft on the floor, and is a single story, but the roof is as tall as the 2 story next door. I live in a "master planned" community. Unfortunately the "master" was a master of building cookie-cutter McMansions, not efficient housing. I'd not have bought it at all if it weren't for the potential for money to be made there, to fund my next house. The area I'm in is growing in leaps and bounds and property values are jumping even in this slump. I'm really hoping the housing market takes off again in the next 2 years, the more I make the more efficient the next house can be. Anyhoo, I digress. The dryer vent goes up the wall from the middle of the house, then takes a 45 degree to dump out through a roof vent about halfway up the roof. Smart, wasn't it? Kinda jealous of my neighbor's house, his dryer is right up against the outside wall and vents right there.

From the reading I've done, looks like I really can't get an idea on how many batteries I need, or how many panels, until I know what appliances are going in and how big a load I'll have. No matter on that, but I do think AGM batteries will be how I store power. Will also store them in a block house instead of a metal shack now. Was also going to have them close to the house, but will set it back a ways now.

Telco · August 2007

Re: Starting from scratch

Well. I think I'm going to have to rethink my whole plan now. Larger house, less HVAC, interior gardening. WOO HOO! Fresh air and fresh veggies year round, with the best kind of heat available; radiant heat. Best of all, I can build a large part of the house myself! Much better than building a house with tons of insulation, then having to control the environment aggressively with lots of solar panels and wind!

Starting from scratch

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