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I have been thinking about the solar option some more. For one thing solarhome.org pump is very inexpensive. I figure after shipping it may cost $50. Then I would need a well pressure tank. Funny thing is, I could buy the same AC pump I have now on eBay and just use the tank. I did not buy the first one that way because the eBay pumps are all returns. (replace return with, does not work.) Cost, less than $30. The total would be about the same.

About that wasted solar energy issue. A thought had occurred to me, I waste summer solar production right now with my solar lights! The pump draws almost 10 amps @ 50 psi. That is about 120 Watts. Better to think in amp hours any way. My battery is a 75 amp hour battery. But, I am sure the capacity is less with a higher current draw. My lights use about 2 amp hours per night, if I remember correctly. On a sunny day in the summer I replace 6 amp hours or more. That leaves me with an extra 4 amp hours.

Gallon calculations: This is a possible deal breaker. Lets say the little DC pump uses 8 amps @ 20 psi and produces 3 GPM. If I want to water 10,000 Sq. Ft. @ 1″, I need almost 6000 Gallons. I question this amount of water since when I do water my bill never shows that high. Let’s use a third of that. Beside if I need to water more than that means the sun is out more. 🙂 2000 Gallons @ 3 GPM = 10 hours! See the problem. 10  hours x 8 amps = 80 amp hours. i.e. Not going to happen.

Now what if I only watered the front yard. It may only be 3000 Sq. Ft. That would work out to be 3 hours using the same fudge factor. That would drain the battery by 3 hours x 8 amps = 24 Amp hours. Not unreasonable. But I could only water once a week.

All in all, I will stay with the AC pump. Sure it uses 700 Watts when running. But it pumps four times as much water.

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This past December killed the old battery. The system ran almost continuously for almost three years. Not bad, but why did the battery fail? First off, cloudy winters days left the battery very weak. Then you have the cold temperatures. A fully charged battery would go for about five nights. Winter can have cloudy day for ten or more in a row. During the month of December and January the light would be off for days at a time. So basically, I had a drained battery in the cold. Not a good idea. But SLA (Sealed Lead Acid) batteries don’t have a long lifespan anyway.

Now, from data in my area, a sunny winter day will give you about 80% or more power as a sunny summer day. The main reason is temperature. Cold sunny days produce more because heat degrades the solar cell output. This colder temperatures help to offset the fact that the sun is not above the horizon nearly as many hours in the winter. What kills the average solar insolation in Indiana is the clouds. If we did not have the cloud cover, we would have double the average insolation. (Maximum recorded December insolation from ’61 to ’90 was 3.7, almost a 50% increase over average)

My new battery is not a SLA. I can and will perform maintainance.  I purchased a trolling motor battery from Wal-mart. While not a true deep-cycle battery, neither was the price. The old battery was 22aH, now I have an 85aH. I should be able to go almost 20 days before the lights go out. I will need more days of full sun to recharge but I think this is a good trade-off. One sunny day yield two nights with lights. A light overcast would be about one half to one. In the summer I will over produce. But I have an inverter attached to the system so I can find ways to use that. Winter, I think I will turn the night light function down from 4 hours to two total hours. That should help with battery life too.

The nice thing about a solar powered pond is that the pond pump is off during the winter! I only have to design around the spring summer and fall.

First design thought, I will not run the pump at night. I would say I would run it from 9am until 6pm.

Second design thought, AC or DC? An all DC system would be good because of no inverter losses. Even so, inverter losses are only about 5% on average. Because of start-up currents I would have to oversize my inverter to compensate. That means more money for an inverter. I do like the keep it simple approach. One less item to purchase and maintenance. DC system it is.

Third design thought, 12V or 24V. This is a little harder. It really depends on total system wattage. I have been looking at boat bilge pumps. A 2000 gph pump draws 8.4 amps @12Vdc. That is only 100 Watts.  The same size pump at 24Vdc draws 4 amps. That is 96 Watts. This is a small difference of 4 watts but it is worth noting. Now comes the charge controller. I want to use a MPPT type controller. The Sunsaver MPPT controller has a better efficiency @24Vdc. It will do both voltages. So I could start at 12 VDC and upgrade to 24VDC later.

Forth design thought, No controller, No batteries? They sell linear boosters for just this, pumping water. At about $100, this would be cheaper then batteries and a controller. Since the units are sized in amperage instead of voltage, it is better to get the 24VDC pump. All pumps do the same amount of work so the 24V pump has half the Amp rating. P=I x V

What Have I come up with?

  1. Rule 24V bilge pump – $125.
  2. Linear Current Booster PPT 12/24 – 7V – $100
  3. Solar Panel ~120W – $500? (Slightly Over sized) Still looking for a deal. Shipping is what gets you.

So for about $700 I cold have a nice pond setup. For reference, my father in-law has a small pond. He runs his pump 24/7. It adds about $20 to his electric bill each month. Another issue I had not mentioned, I don’t have to or want to run the AC line for the house up to the pond. No trenching or conduit or GFCI outlet or or or… Just a water fall and solar panel.

I read somewhere that these films can damage your windows. But if it means I can delay replacing them for a few more years than it would be worth it. My windows are construction grade windows. My guess is the minimum allowed by law at the time. (Like everything else) So if I can get more usable life from them then I am going to try. I don’t want to spend too much but I also don’t want to buy junk. After reading around on the Internet, I have decided on Gila window film from Lowes.

I will wait a few months, right now I want to sun to warm the house. Hopefully, for about $60, I can reduce the amount of heat gain on the south side of the house. This film will also reduce heat loss. Maybe I will buy a roll now and apply some on the backside windows. As inexpensive as it is, it is worth a try.

According to Gila’s website it is safe for double pane windows.

As per a previous blog, I know that the 160 mile battery pack will need about 400kW Hours. This calculation will use the average solar insolation value and power would be supplied through a grid tie system. The 400kW hours was an inflated number to begin with. For a grid tie system, I will use 95% efficiency.
At my location, I have an average of 4.6 sun hours (Latitude -15). I need to make 400kW hours / 0.95 = 420 kW hours. I need to generate (420kW hours / 30 days =)14kW hours a day. What size array do I need? (14kW / 4.6 hours) I need a 3kW array. The generic installed cost is about $8 a watt for a grid tie system. A system would cost me $24,000 installed. Then take 30% off of that in the form of a Federal rebate. You get  $16,800. Not bad. The simple payback would be 47 Years. Maybe if you sized a system for the car and the house, the cost per watt would reduce to a more reasonable number. Say $6 per watt (I laugh to myself and say no way.) Then the cost would be $12,600. Even better! But just remember, this is at today’s energy rates. Who knows what they will be at in the future.

Today is a good day for my conundrum. It is sunny and the wind is blowing an average speed of 12mph. The windmill in question is a skystream 3.7. At an average wind speed of 12mph I would be producing 400 kWhrs a month. I am guessing the cost installed would be $18,000. What does $18,000 towards a solar system get me? At about $10 a watt installed. 1800 Watt system. Of course, actual prices may very. 🙂 I have an average solar insolation value of 4. That is equal to 120kWhrs per month. Wow, did not see that coming! The one major problem is the neighbors, I don’t think they would like it if I got one.

Link to someone in Ohio that purchased one. His total cost was $15,087.00

After looking at that site, makes me think that 400kWhrs is way high. There maybe a lot of hot air in wind power. Hey, at least with solar all I have to do is place the panels in the sun. Don’t believe manufactures numbers. It is best to find someone else that will have similar conditions to yours.

What about a Vertical Axis Wind Turbine (VAWT)

PacWind

Urban Green Energy

Mariah Power

Cleanfield Energy

Wind Terra

I like the last link the best. Why? If I can mount it on top of the house and not have to install a pole. I will save money. But, it can’t keep me up at night during high winds.  i.e. it won’t shake the house. Major issue wit mounting on top of the house is weight. Some of these turbine weigh 500lbs.

At half the price, and 40% of the power…. It still is easier to put up panels. Maybe not as cheap per watt but easier. I believe that I am right smack dab in the middle. If I had higher than 4 solar insolation, I would get solar panels. If I had higher then 12mph annual wind, I would get a windmill. What I really need to find is a site that would have done this for me!

The first major question one would need to answer is: How long do I plan to be without power? Less than 12 hours? More then 12 hours?

If you answered less than 12 hours – Solar backup generator.

If you answered more than 12 hours – Regular backup generator.

I am not going to talk about regular generators. We want to know more about a solar backup generators. What do I need to make one? How much will it cost? What can I power with it and for how long?

Let’s start with the last question first. To begin with, this system will only run a few lights, a TV and a laptop. This will not run your entire house. Just like  most store bought generators will not either. I, personally, would like it to be able to power my refrigerator for 4 continuous hours. In addition to two lights and a small laptop for 4 hours. The refrigerator uses 160 Watts while running. Two lights are 25 Watts and my netbook charger use about 15 Watts. That is equal to 200 watts. For a total of 800 Watt hours. I would use a 12 Volt system for this small application. 800/12×2=133 Amp Hours of batteries. I would round this up to at least 150 amp hours and purchase a battery close to that number.

Now for the solar panel. Since this system will only be use intermittently, I can get away with using a simple solar rule. 1 Watt panel power for every amp hour of battery. No charge controller is required. I would need a 15 Watt Solar Panel.

What does this cost.

Cheap Wal-mart batteries x2 = $100

20 Watt solar panel (No 15W Availible) = $200

Cheap AC/DC inverter 600W =$60

All total for less then $400. No gas, no fumes, NO CARBON MONOXIDE.

Xantrex XPower Portable Powerpack 1500

Xantrex XPower Portable Powerpack 1500

Or you can buy this. All ready to go. For almost the same price. Only problem, no solar panel and smaller battery. On the positive side. Very nice inverter! Nice cart!

Sure, this will cost more then a regular generator. But, your fuel is free. In a pinch, you could always hook the inverter up to your car battery. Then start you car when the battery starts to get low. Not the best solution but good in an emergency.

Light Bulbs: eBay $70 for 20

Solar Panel: Kaneka 60 Watt (GSA) $250

Solar Controller: BZ Product MPPT 250HV $150

Batteries: Wal-Mart Deep cycle x2 $100

Why did I choose these items. As we calculated from before, I needed a 27 watt panel and 60 amp hours of battery. I over killed it, BIG TIME. Why? I want to have a small back-up solar generator that’s why. Let me explain.

If the power goes out in the summer time, I don’t want my refrigerator food to go bad. It would only take one extended power outage  to pay for the overage. Additionally, the shallower discharge of the batteries will make them last longer. Since they are Wal-Mart cheapos, they will need the extra care. The controller can also handle 3 more solar panels if I decide to add more solar “stuff”. Personally, I think it would be great to have the garage door on solar power. Then if the power goes out I can still open the door. Lastly, the controller is a MPPT type, I just wanted to get one.

Overall, my price has been exceed but I think my satisfaction will be increased as well. FWIW – Version 1.0 of my solar light have been dark for about a week. It has been cloudy and the controller is in Low Voltage Disconnect until the sun shines again. This would not happen with this new design.

Next in the series: My Solar Landscape Lights 2.0 (Installation) -not until the spring-

Just for your enlightenment. Version 1.0 is located here.

My Solar landscape Lights V 1.0

Since my first attempt has gone very well. I thought I would consider another venture. I would like to keep the cost to around $500.

So how many lights am I going to light up? Well, I was at my local home depot and picked up a cheap Malibu light kit for only $8. It was an open box sale and appeared to have everything in it. (Actually, I purchased it for the light bulbs!) They want $5 for four replacement bulbs! The kit had 20 in it.) I also have a few light from another similar kit that I did not use. AND, I have the original light in the front of the house. In other words, I could have 50 lights. I will plan for about 40.

If I run my lights for 3 hours in the evening and I hour in the morning. (4 Hours)
The light bulbs use 0.5W of 12VDC. This would be …. 40 bulbs x 0.5W x 4 hours = 80 Watt Hours
80 Watt hours is a good amount of power for lights.

Solar panel size.

Since most controller have selectable nightlight controls, I will use 3 hours of solar insolation. This means in the winter I need to output less number of hours of light and in the summer I can output more number of hours of light.

Panel size would be…. 80 Watt hours / 3 hours = 27 Watts (Usable Power)

What is usable power? If you look at a 30W 12V solar panel power specs you will note that current short circuit is 1.80A and voltage is zero. The panel produces maximum power at 18V with a current of 1.67 Amps. Power = Amps x Voltage. (30W) If you use a regular solar controller, all it really does is connect the solar panel to the battery. This means you are down around 13V. 13V x 1.8 Amps = 23 Watts. You lose a potential 7 Watts. Introduce the MPPT (Maximum Power Point Tracking) Solar controller. They cost more put will get you back most of the 7 Watts you lost.

With the calculations from above I will need a sightly larger then 30Watt panel if I use a regular solar controller.

Battery Pack Size

A good rule of thumb has always been 5 days storage. Another good rule of thumb is never go below 50% of full charge. If I use 80 Watt hours a day. And I need to add about 20% for battery inefficiencies and wire losses… 80 Whrs / 12V = 7 Amp hours. 7 amp hours /50% X 120% x 5 days = 60amp hours.

Now I know what size of components to buy. All I need to do is figure out what to get. The current debate has been a regular controller vs. a MPPT type. I and thinking I will go with the same one I have in the version 1.0 of the landscape lights. It works very well.

To be continued! (component section and justification)

All of you know that the government has “Bailed Out” the financial system. But, did you know that some very crafty lawmakers placed the energy tax credits into the the bail out bill. That’s right! And… they will expire at the end of 2016! What does this mean for most Americans?

First: This is a tax credit. When you file your personal income tax return, this will reduce the tax you pay. i.e. this comes off the bottom line, not the top.The best part of this is, if the federal tax credit exceeds tax liability, the excess amount may be carried forward to the succeeding taxable year. So you may not have to pay taxes for a few years if you get a good sized system.

Second: What amount is the credit? 30% of the total costs associated with the installation. And there is no limit like the original incentive! Roll out the solar panels please.

Thirdly: Solar hot water still has a $2000 limit. This should be fine because the total cost of the system would have to be over $6666. Most systems do not go over that amount anyway.

What does this mean for us? Start planning and researching, alternative energy is not as far out of reach as you think? This is only one slice of the money pie. You may live in a state that has incentives too. Check out this site to learn more.