Need alternative energy at home. Need advice....

doni49

I need to do something to help reduce my electric bills. If I could eliminate them completely, that would be fantastic. But I'd be satisfied with a decent reduction. But my head is spinning from trying to digest all that I've read over the past few weeks.

At an absolute minimum, I'd like to have the system provide power for my HVAC system. (A/C during summer and elec heat during winter.) I'm also leaning toward building a couple solar heaters to help during the cold months.

I live in a mobile home and would really rather not put panels ON the roof but I'd be willing to mount posts in the ground to support raised panels though.

I'm also toying with the idea of building a DIY vertical turbine which would also be mounted on a tall post (although I'm not sure how high I'd have to make it).

I don't know if I should just do one of them or both (I thought the wind power could supplement the solar so I'd still generate power at night & on cloudy days).

I'm hoping for some advice on 1) how big a system I should be looking to put in and 2) what are your thoughts on the wind vs sun issue?

I need to keep my start-up costs minimal. But it would be nice if it would be expandable later.

TIA!

Cariboocoot

Re: Need alternative energy at home. Need advice....

Welcome to the forum.

What we'd really need to know is your location. Another thing would be how much power your using now.

Skipping ahead, chances are pretty good that any type of alternate energy isn't going to save you a dime. Oh it may lower your electric bill, but contrary to what some would have you believe it isn't free. There are some substantial capital costs and the lifespan of the equipment is limited. Wind is particularly expensive and not such a sure-fire return.

Usually grid-tie solar is your best bet, especially if you have incentives such as tax breaks or rebates where you are. But it doesn't come cheap.

What will be your most economic return would be conservation. This will start with a Kill-A-Watt meter and a lot of measuring of plug-in devices to see just which are the power hogs. Money invested in conservation of all types will be a better return than money invested in generating your own power.

doni49

Re: Need alternative energy at home. Need advice....

Yes there are incentives (tax breaks and power co rebates) available.

I'm in central Mo. I'll have to dig out a power bill.

doni49

Do the deep cycle batteries make the room hotter?

I'm already having to deal with the A/C running too often (making extremely high elec bills) so I'm worried about the possibility of the batteries generating more heat themselves.

TIA!

BB.

Re: Need alternative energy at home. Need advice....

Welcome to the forum Doni,

I moved your two threads into one--They both really are about the same thing--Saving utility costs.

Lead Acid batteries generally do not generate too much heat--They are most efficient at and below ~80% state of charge (call it ~10-20% of charging energy goes into waste heat). Above 90%, upwards of 1/2 of the charging energy goes into making heat.

In general, off grid solar (i.e., with a battery bank), will not save you money if you already have utility power on site unless you have a large minimum monthly charge (i.e., at the end of a long power line, some utilities are hitting $50-$90 per month minimum charges, etc.).

As Marc (Cariboocoot) says--Conservation and understanding your present energy usage/billing from your utility is your first task. It is almost always cheaper to conserve (insulation, buying new ultra-efficient appliances, etc.) than to generate your own power.

Just as a starting point, what would you do different if your power costs were on the order of $1.00 to $2.00+ per kWH (i.e., ~10x your current $/kWH costs for typical utility).

With modern mini-split AC systems (and heat pump), it is becoming possible to use solar electric power power to cool/heat a well insulated cabin/efficient home. And there are other things that can be done to reduce energy usage.

After you have conserved and better understand your (hopefully greatly reduced) loads--Then you can look at solar power. Grid Tied (no battery bank) can be cheaper than utility power--However, when the utility power fails, your GT system turns off too.

Off Grid systems (or hybrid systems that do GT and OG power) are also possible and can be very nice for people with "unreliable" power (ice storms, etc.)--But it is not "cheap" usually.

Grid Tied systems need a good utility tariff to be cost effective. Not all utilities support "Net Metering" (best for consumer) and may have other plans that offer less return on investment or even make utility connected "GT" power illegal.

People that have never addressed conservation before--It is not unusual for a home owner to save upwards of 50% of their energy usage.

-Bill

Cariboocoot

Re: Do the deep cycle batteries make the room hotter?

Well, they do. So does everything electrical because as current flows heat is produced. More current = more heat. It doesn't matter if it's in/out of batteries or through wires or an inverter ... or a light bulb.

doni49

Re: Need alternative energy at home. Need advice....

BB. wrote: »

Welcome to the forum Doni,

I moved your two threads into one--They both really are about the same thing--Saving utility costs.

Oops. I saw that they were in the same thread and thinking that I had accidentally done that myself, I deleted the second one from this thread and recreated it as a new thread. S

BB. wrote: »

Lead Acid batteries generally do not generate too much heat--They are most efficient at and below ~80% state of charge (call it ~10-20% of charging energy goes into waste heat). Above 90%, upwards of 1/2 of the charging energy goes into making heat.

In general, off grid solar (i.e., with a battery bank), will not save you money if you already have utility power on site unless you have a large minimum monthly charge (i.e., at the end of a long power line, some utilities are hitting $50-$90 per month minimum charges, etc.).

As Marc (Cariboocoot) says--Conservation and understanding your present energy usage/billing from your utility is your first task. It is almost always cheaper to conserve (insulation, buying new ultra-efficient appliances, etc.) than to generate your own power.

Just as a starting point, what would you do different if your power costs were on the order of $1.00 to $2.00+ per kWH (i.e., ~10x your current $/kWH costs for typical utility).

With modern mini-split AC systems (and heat pump), it is becoming possible to use solar electric power power to cool/heat a well insulated cabin/efficient home. And there are other things that can be done to reduce energy usage.

Even if it just generated enough to power the HVAC system, I'm sure that would go a long way. And that brings up something else I was actually thinking about: I've been concerned about power outages leaving me without heat. So I thought maybe I could at least make this system provide the power for the HVAC and even if the solar/wind doesn't generate enough power for to be the SOLE power source, the batteries could be charged from the grid -- that ay I'd never have to worry about losing heat or A/C (unless the outage is extended beyond the system's capacity).

BB. wrote: »

After you have conserved and better understand your (hopefully greatly reduced) loads--Then you can look at solar power. Grid Tied (no battery bank) can be cheaper than utility power--However, when the utility power fails, your GT system turns off too.

Off Grid systems (or hybrid systems that do GT and OG power) are also possible and can be very nice for people with "unreliable" power (ice storms, etc.)--But it is not "cheap" usually.

Grid Tied systems need a good utility tariff to be cost effective. Not all utilities support "Net Metering" (best for consumer) and may have other plans that offer less return on investment or even make utility connected "GT" power illegal.

People that have never addressed conservation before--It is not unusual for a home owner to save upwards of 50% of their energy usage.

-Bill

As to conservation, I work to conserve where I can --things like programmable thermostat that lowers the temp by 4 degrees at night & while I'm at work. There's almost never more than one light on in the house and every light is CFL.

Cariboocoot

Re: Need alternative energy at home. Need advice....

Want some more bad news? Of course you do!

HVAC systems are big power users. Air conditioners have compressors that take big start demands and use plenty while running. To some extent it's unpredictable too, as the power demand is dependent on how often it cycles and how often it cycles depends on how hot it is.

If you were looking at a grid-tie system you'd be looking at about $3 per Watt (depending on quite a number of factors unfortunately). But a grid-tie system doesn't produce anything when the grid goes down. For that you need batteries, and that ups the price.

For emergency back-up power a generator is usually a much better value for the money.

BB.

Re: Need alternative energy at home. Need advice....

You really need to look at your "situation"...

Older appliances/HVAC systems vs "modern" energy star rated systems can use 1/2 the electricity of older/"failing" units.

If you have electric hot water, there are heat pump based water heaters that can use 1/2 (less) electricity vs resistor based water heaters.

Using exterior awnings over south/west facing windows, landscaping to block sunlight, etc. can be a big help.

Using a laptop at 10-20 watts vs a desktop at 200+ watts, using a thermos to "cook" stews/soups, etc. all save energy on initial use and save money in the summer (less heat for the A/C to move outside).

You can also look at your rate plan(s) and see if you can use Time of Use billing (i.e., if you can avoid high power usage during week day afternoons in the summer).

In general, a very efficient home/cabin using an electric refrigerator/lights/laptop/washing machine/well pump can do it for around 3.3 kWH per day (or ~100 kWH per month). Use natural gas/propane/etc. for heating/hot water/cooking.

So--That can give you a number to aim at.

But add A/C, electric hot water, cooking--You are probably looking at ~1,000 kHW per month (plus or minus). That is a big system and for Off Grid power, is almost never a good "investment"--There is a lot of up-front cash, and replacement batteries (typically around 5-7 years for "average" batteries/usage). And every 10+ years, new charge controller/AC Inverter/power electronics.

With Solar Power--It is all about the loads.

-Bill

PS: Don't worry about posts--From my experience here, I think it was better to keep the conversations in the same thread for now.

bill von novak

Re: Need alternative energy at home. Need advice....

doni49 wrote: »

Even if it just generated enough to power the HVAC system, I'm sure that would go a long way.

That's a little backwards. The FIRST thing a system will be able to do is generate enough power to run a few efficient lights, charge a laptop, run a small fan etc. That's a few hundred watts and people build such systems often for their RV's or cabins.

If you spend more you might be able to run (or offset power from) refrigerators, TV's and larger loads. If you have a large (=expensive) system it might be able to run your HVAC. A/C is often the largest load in a warm-climate home.

And that brings up something else I was actually thinking about: I've been concerned about power outages leaving me without heat. So I thought maybe I could at least make this system provide the power for the HVAC and even if the solar/wind doesn't generate enough power for to be the SOLE power source, the batteries could be charged from the grid -- that ay I'd never have to worry about losing heat or A/C (unless the outage is extended beyond the system's capacity).

Again, the system you would need to run a central A/C or electric heat would be enormous. (Tens of thousands of $$) However, the cost of generating enough power to run fans or the blower motor for a natural gas furnace is much lower, and might be practical.

If you are serious about reducing electric bills and having a backup, the first thing to do is to switch over to a much more efficient A/C and an alternative source of heat (propane, NG, oil, even pellet stove.) Solar hot air or solar hydronic are good alternatives as well. Mini-split A/C systems are good options, and will keep one or two rooms cool enough to be livable. Replace your appliances (refrigerators, washing machines etc) with energy efficient or non-electric versions, and replace your lights with CFL's or LED's. Every dollar you spend on efficiency will lower your electric bill much more than it would if you spent that same money on solar.

Then, when you have done all that, THEN consider a solar power system. The system you will need will be far smaller and more affordable at that point, and a relatively small battery bank will be able to run you for a few days when you lose grid power.

waynefromnscanada

Re: Need alternative energy at home. Need advice....

Welcome to the forum!
As the others have been saying/hinting at, off grid is generally not the way to go to save money if you have grid available. Conservation and new energy efficient appliances is.
It's very unfortunate that there are people out there spreading the idea to those who are unfamiliar with solar, that all they basically need do is hang a $300 solar panel on the roof and all their energy problems are over. Oh that it were true.
As has so often been said by those who know, the secret to living off grid is to conserve, conserve, conserve! It's FAR cheaper to conserve a watt, than to build a solar system to supply that wasted watt. Unfortunately many of us have been brought up with waste being such a huge part of our lives that we don't see waste, can't recognize it. To be honest, living off grid requires a whole new mindset, a whole new way of thinking about energy use. It's a way of life that most people can't comprehend.
But many of us do make it work and are happy with it. But it requires a different way of life, a different lifestyle.
Oh, and re keeping thoughts about the subject in one thread, it works well. Otherwise everyone has to keep jumping all over the place searching for the latest comments and ideas on the subject.
I wish you well in your quest for knowledge, and I can say you came to the right place. The people here know what they're talking about, don't BS or steer you wrong.

solar_dave

Re: Need alternative energy at home. Need advice....

Welcome to the forums! Stick around and start to learn how you can do what you want.

1). you have to do the conservation regime. Energy Star appliances, high seer AC units, CFL/LED lighting, Increased insulation, any thing you can do to reduce your consumption has to be the first step. Mini Split AC units are great for cheaper AC operation.
2). you can start to roll off some of your costs with DIY projects for Solar thermal hot water or space heating. As stated before the heat pump hot water heaters can reduce consumption but with some limitations, like they need to be in a place that is generally warm and a place that could be cooled by the heat pump.
3). you have to measure your consumption, that could be as simple as a power bill over a 12 month period or as complex as a full blown data collection system. The former is usually enough to get you started down the right road.
4). unless you have really unreliable utility supplied power, drop the battery sets from the equations. Batteries are expensive, large maintenance item and increase the amount of power you have to generate to cover your consumption because of losses in the battery system. Also you have to build a battery system for the worst case scenario of consumption and maintain a generator as a back up for no sun conditions as to not kill you battery bank. Generally with a good utility tariff for net-metering you can utilize all the power you generate in a grid tie system. This is not the case with a battery based system, if it is sized for the worst case scenario then lots of power "falls on the floor" on the good days.

Once you have done all that then you have a chance at building a solar PV system to offset part or all of your electric consumption. (note I left off wind, notoriously failure prone and full of charlatans telling people it will work) Wind is hugely expensive for the given output, usually requires a large tower to get up into clean air and requires lots of maintenance.

One clear advantage to grid tie is the ability to load shift and carry power forward. My tariff allows me to carry power from month to month and then settle the excess at years end. In the AZ desert my consumption for AC sky rockets in the summer months. So we looked at a balanced system that would cover our annual consumption. We generate more power in the spring months and bank that towards our summer consumption. There is no way I could have a battery based system to meet my summer consumption. We are talking well over 120 kWh a day in peak cooling season. Our large PV system only generates at best about 62 kWh a day in peak cooling season. We would have to more than double the array size to even attempt it and then have a pretty good size generator for support purposes.

It is interesting to note that after we got our grid tie system operational we continued to implement power reduction/conservation technologies. This allowed us to add a pair of plug in electric vehicles which we charge off grid tie system. In the event of a sustained power outage we have a pair of inverters that can be wired to the cars 12v systems to keeps essential things running like freezer and fridge.

SolInvictus

Re: Need alternative energy at home. Need advice....

BB. wrote: »

Using exterior awnings over south/west facing windows, landscaping to block sunlight, etc. can be a big help.

The cheapest thing you can do to reduce your air conditioning load is to block sunlight from directly entering your windows during summer. In addition to awnings and landscaping, insulated window inserts with aluminum on the sunny side (like an automobile window shade) work well. They also insulate the window during winter.

Paint your roof white.

waynefromnscanada

Re: Do the deep cycle batteries make the room hotter?

I'm lucky where I live, in Summer the sun is high overhead and doesn't shine in the windows. In Winter however, it's low on the Southern horizon and pours it's free heat into my life. Fall can be a bit of a problem though, as the sun heads South before the temperatures do. On those days I raise my black venetian blinds and lower the white ones if the sun is shining, + IF the sun is shining and it gets too warm inside in the Fall, solar runs the mini-split in AC mode for free on those few days.

Skippy

Re: Need alternative energy at home. Need advice....

Just thought I would weight in on this thread. I have been actively trying to reduce my electric bill for a while now, and so far it's not too bad. . . except in the winter - heat pump house heating - takes alot of power and I know I will NEVER be able to run it on solar or wind. . .

So far what I have done :

1. made sure the coils of my fridge are free and clear to do their thing, so it does not overheat, then wrap the fridge in 2 inches of styrofoam - cuts the electric usage in half - most people HATE it - it looks ugly. Make sure it's on there nice and tight or you get mold growing in between !

2. put in an apricus high efficiency solar water heater - with an on demand water heater as a back up. if no sun, the water heater only comes on when - 1. I have it off of bypass mode - 2. only when the water is running. It still takes alot of power - so it will stay on the grid - no way I can run it off solar . . .

3. I am going to be putting a rocket mass heater into my work shop this summer, as a test case to get it past the building inspector and insurance companies in my area, if that all goes as planned, I may be putting one in my house - the idea being if you don't want to use the electricity - get off it. Use something else. In my case, I am using 900 kwh per month (or more) to run my ground source heat pump (-25 C this winter - its been COLD ! )
Depending on your skill level - have a look at rocket stoves - you may not be able to put in a rocket MASS heater, as they weight in at about 2 tons - but a rocket stove by itself may do the job. . . just a thought.

4. I have also done all the standard stuff - everything is on power bars that can be turned off (no phantom loads) - CFL lights thru out - with a few LED lights in the more well used areas. . . about the only thing running on its own, is the fridge - and a ceiling fan - and that adds up faster than you think over 24 hours. . .

5. Used that same 2 inch thick styrofoam that I used on the fridge, and covered most of my windows with it. Since glass has an R value of what ? R1 ? It can use all the help it can get. . . good in the summer as well for keeping the place cooler . . .

I have put in my solar panels, and once this really cold winter is over, I will continue with the install - but it will only run my kitchen and some lights - I hope - there are no garantee's I will be able to run everything I want too since I use more than I think, and will make less than I need. . .

just my thoughts.