has anyone done any of the amazing stuff on the Green power

[monster]

hi

i've been looking at renewable systems for a long time to try and figure out what was the most practical setup for my situation (rented house, moving house every year, living with girlfriend, no desire for large capital expenditure). i've really been inspired by some of the easy DIY stuff that dan rojhas has on the green power science youtube videos and ebay items. im thinking about a hot water system hooked to the hot water tank or a solar charging system for my electric bike.

has anyone here done any of his or similar projects?

 

[spinningmagnets]

Take a scan over at http://www.builditsolar.com, and also http://www.otherpower.com Probably the best bang for your buck is a solar hot water preheater.

Find a water heater tank thats in good shape (sometimes a fairly new electric unit is replaced with a gas unit) Build a lengthwise box to hold it, with a lens made from a sliding glass door. It should face the south. Run your hot water heater lines through this tank first, then through an insulated pipe into the heater. The inside should be painted black with high-temp barbeque paint (except for the glass, of course!)

Water from a pipe that comes out of the ground is around 55F, and water coming from the solar pre-heater should easily reach 120F+ in the spring, summer, and fall. If you pay someone to do it and buy new materials, its expensive. But if you do most of it yourself and scrounge scrap materials it can be done very cheap.

In winter, if you have frequent sun in spite of the cold, the solar air heaters work well. Inside the panel are stacks of aluminum cans that have a hole in the top and bottom, forming aluminum columns under the glass (painted black). they really work (heated air rises). You can often find free windows and glass doors in buildings that are scheduled for demolition. just ask around. I've even seen horizontal-flow units with a PV-powered fan so when the suns out, it flows. Suns obscured or night-time, the fans off.

 

[dnmun]

you will be limited in what you can do if it is a rental property. no landlord is gonna let you work on the plumbing without supervision and then you will have the liability too if it ruptures and floods the house. which could cost you considerable tens of thousands of dollars to have repaired. also all plumbing needs to be supervised by city inspectors and if you are not a licensed plumber then they won't let you touch a thing anyway.

i regularly see used hot water panels selling on CL for less than the scrap metal value of the copper in the panels.

this house here is a rental and i would never trust the tenants to manage a solar hot water system so i would never install one here and most renters have no interest in paying extra rent to pay for such improvements anyway.

the easiest way to create energy conservation is to just use less. some people can use 60 gallons of hot water for a shower but 6 gallons is enuff. turning off lights and using flourescent bulbs can easily save 200-400kWh/mth for those who leave a lot of big bulbs burning.

if you have a gas water heater, you can improve the efficiency from 40% for a tank type to over 95% for a derated bosch/junkers flow through boiler like i use. that reduces the cost of heating water from 1.6 cent/gallon down to .5 cent/gallon. assuming 1500 gallon/person/mth that can add up fast too.

instead of a big AC to cool the house, use an attic fan to suck in cool air at night and then close the windows in the morning at daybreak to seal in the cool air and seal out the hot air during the day, and use reflective film on the windows to keep out the sun's heat. that can save another 1,000-2,000 kWh/mth.

in winter, seal the leaks and keep the heat off as much as possible. use an electric blanket if you get cold by letting the house cool off into the 50s at night. turn the heat on so it is blowing heat when you get up and turn it off totally when you leave the house for work or school. this is so critical since most people just leave the furnace turned on day and night.

so just simple behavioral changes, kinda like relearning the tricks people used to use to conserve before energy became so cheap after WW2 that we have been trained to waste it as a way to feel good. kinda like the need people feel to drive a huge SUV or fat car/truck when a bike or small car would work better but it reflected badly on you if you conserved.

just unplug your dryer and buy a clothes drying rack for $9 at walmart. that will save $15-25/mth if you use the dryer a lot.

so just small changes in how you manage your energy use, even with no 'lifestyle' changes can knock down energy consumption by 50-70%.

to summarize best case savings: for typical family of 4
dryer $25
lights $40
heat and AC $100 avg
hot water $65

so you would have an extra $230/mth to spend on ebike stuff. that will allow you to reduce gasoline usage dramatically too if you have to support cars.

if there was a national conciousness as well as conscience about wasting all the energy we now consume it would immediately stop the global warming problem and if the natural gas now used to make electricity was freed up for the transport fleet, then the usage of CNG vehicles could expand to cover all the uses which would not be served by plug in hybrids.

without any 'lifestyle' changes!

 

[dogman dan]

Definitely the solar air heaters can be easy. since I own, I attached mine to a south wall on the house, but the collector is simpe to make from scrounged stuff and a few sheets of plywood and insulation, and then can be ducted to a window. This does assume there is some yard space on the south side, the landlord is ok with it, etc. Mine circulate by convection, but a very small fan might be needed to make the air move in a ducted setup that had the inlet and outlet at the same height though a window.

I used corrugated metal roof panel painted black to collect the heat, and transfer it to the air, but the cans look like a good way too. Since it's so sunny here, mine worked amazingly well, and cut my heat bill in half easy, using 5 sliding glass door panels for collection area.

I need to get cracking on a pre heater for my water next.

solar charging for the bike is a good idea, but not so cost effective unless somehow you get the panels "freebie" . If you think about it, the green living value of riding the ebike instead of taking a car is soooo huuuuge., But renewably charging the bike, which may take less than a dime, is kinda dinky. I think of it as like, riding the bike,,, 90% improvement. Charging the bike solar, ,,, 10% improvement. It's a good thing to do, but just has a small impact on the planet compared to the bike iteslf. Another way to look at it, the green equivilant of solar charging a bike might be similar to replacing one 100 watt bulb with a compact florescent bulb. Changing the bulb costs like 3 bucks. Buying a set of panels to charge an ebike may cost $300-$500. Putting that same money into the house stuff, like solar heat, or even something super simple like a foam insulation sheet to block a window at night in winter will get you a lot more green for the buck.

Of course, there is a huge value in bragging that my ride is 100% green, and the satisfaction may be worth every penny. If so, go for it. I keep thinking about doing the same sort of thing, to put my extravagance, the tv , on solar just to feel better about using it so much. But for now, I will continue with putting money into insulation and such since I do own the house. The low hanging fruit like a solar water preheater will come first.

 

[dnmun]

actually you can figure in rough estimate how much it would cost to buy the PV to charge your bike for a daily 30mile round trip. assume $5/W for the PV, or $15 for guvment work.

assume lazy butt, lead wrist, ride with traffic, 20Wh/mile so usage 600Wh/day.

but beside the fact that the bike will be gone during the day when the sun is out to charge it, then you have to maintain some sort of charge pumping electronics which will eat up the energy to get it hot enuff to go into the cells, but we can assume the next level of digital controlled BMSs which can be built to allow the entire pack to be charged in parallel and then switched back to series. that will allow most of the inverters to pump the charge a minimal amount. assume 85% efficiency.

dogman has more daylength and solar irradiance and total days of sun cover than any of us.

assume 5 hours/day 12mth avg.

within the alotted 5 hours he will have to store the (600/.85)Wh so the panels need to produce 141.17W/hr.

that would cost $705.88 dream case.

savings over electricity from the plug, .6x.13= 7.8 cents/day

in 1985 i spent about that much to build a solar hot water system for a house in the mountains in colorado which has 6 3x6 panels, same southern exposure as dogman, paid $300 for the panels used in '85, $400 for 120 gallon tank, $300 for heat exchanger and pumps and delta controller through an energy coop group, one of the energy cooperative things where it was just shared group buy of pumps and glycol and all the other dealer stuff. so around $1200 total since then because one of the pumps was replaced. produced an average of 100kbtu/day energy to the water, 90% of the days are clear there. the coldest days are the clearest.

so that saved an average of 21kWh/day, for electric heating element there at $.13/kWh. about $2.73/day for 24.7 yearsx365 days/year = $24,612

and there was the $10k tax credit available at that time, from jimmy carter's campaign to wean us off the oil teat, because the entire house is passive solar heated so it qualified for the full tax credit. they also use propane for backup heating and dryers and stove, and it costs about $300/yr since they own their own tanks.

so that is the rational for solar, hot water heating and space heating. amory lovins does it at even higher altitude than that house.

save money.

 

[monster]

i love the fact that on this forum we figure out exactly what to do, to get the best out of our cells. i don't think enough people have really done that with PV cells yet. i have bought $60 worth of PV cells just to play with and post about. i think i migh be able to over-clock them with a fresnel lens and some passive cooling.

i might try the air heater idea in winter. i'm worried that leaving a window open to pipe in the hot air will just let all the hot air escape from my house. does the solar heater have to be double glased to trap the heat? is plexiglas ok?

 

[spinningmagnets]

Builditsolar says to use glass or polycarbonate, plexi is guaranteed to deform from heat. Two layers of glazing reduce emissivity losses, but better to start with one layer if thats what you have, and add another layer later. If using glass/polycarbonate put the glass on the hotter inside, and the break-resistant poly on the outside. Tempered glass is best, but if free demolition glass doors are available use em.

Businesses that install new windows/glass-doors often haul away the old ones. They often save them to cut out the old glass in a size they need for a future job. Since they don't know what jobs they'll get they don't cut the used pile until needed, so you can get used glass doors cheap.

Once PV panels are overheated too much they are fried. In the winter time when the air is cold you can get away with some solar concentration by having a mirror or some type of reflector to double the light. Using a fresnel would make a panel much hotter than just a light reflector. I would add a temp sensor with an alarm function ($40 barbeque thermometer with pager)

You can rig the panel so if it gets too hot, the warning signal trips a relay/latch and the reflector flops away from the solar focus. Above the panel you can rig a solar chimney (connected by a flex-tube?). This is where a solar hot-air panel (like in the second post) is made, and the rising hot air draws cool ambient air up across the back of the PV panel. Perhaps enclose the back of the panel with about a half-inch of air-space?. Cold winter air would be drawn up by the solar chimney above it.

I would be reluctant to use solar concentration in the summer. I haven't owned or used a PV panel yet (or wind-gen), but I am in the process of moving to Kansas, so my homework at those two websites the past couple years may finally pay off.

For the hot-air solar-heater, you'd make an adapter to fit in your window so the partially open window is sealed off around the two flex-tubes. The suction line would dangle to the floor (where air is the coolest) pass through the window adapter and then down to the bottom of the heat panel. Hot air rises (with or without a PV fan) and the hot duct would route from the top of the panel directly to the window adapter

 

[deronmoped]

Renting.

Open the windows at night to let the hot air escape, close them during the day. Same thing with the drapes (they sell automatic drape controls) , use them to control heat flow. Use some cardboard covered with aluminum foil on the south facing windows to keep the heat out. Dry your cloths on a cloths line, dry wet shoes in front of the refrigerator. Wash only full loads, wear your cloths more then once, take a military shower (wet yourself down, shut off the water, lather yourself up and then rinse off). Divert the water from the washer to your garden or plants if you are into gardening. Use florescent bulbs (free from the utility company) to save on energy. See what the utility company has to offer in the way of free upgrades to insulation, door and window seals and some even offer to replace old worn out refrigerators for free. The utility companies even come out and will do a energy audit, at that time they usually hand you a bunch of florescent bulbs, maybe even install them for you. Have the landlord trim any trees that may shade the house just before winter hits. Let them grow to shade the house during the summer.

Deron.

 

[monster]

thanks deron but i've already done those things.

another thing i do to save heating bills is put the plug in the bath when showering. the hot water builds up and gives up its heat to the surroundings instead of going down the drain. once it has coolled down, then pull the plug. same with any waste hot water, let it stand first, then ditch it. its probably insignificant tho.