Short Days and Warm Showers

If you’ve been following my blog, you know I use solar to heat the water I use in my home for washing and bathing. It takes about 3 hours of good sun each day to keep up with all of my hot water needs. When we get a few clear days, the water storage gets hot enough that I can go a couple days with heavy overcast conditions.

This time of year, the sun is only effective for heating from about 09:00 AM until about 3:00PM. That’s not a big window, if the day is partly or mostly cloudy. Furthermore, we seem to get a couple of sunny days, followed by 3 or 4 cloudy days. I gave in and turned on my electric water heater for one day in late December. Otherwise, there are days when I have to take a warm shower, instead of a steamy hot one.

For me, this has sort of become a crusade; to try to get by on what the sun provides. It’s not much of a sacrifice. Most of the year, I have more hot water than I can use. However, these short days, combined with overcast conditions, really do test my resolve. Occasionally, in the summer, we get a week of rainy dark weather and I run out of hot water, but it hardly matters, because I take some of my showers outside in the summer, anyway. Hot showers just aren’t as important to me when it’s 90 degrees Fahrenheit (32C).

I just purchased another photovoltaic panel and a new charge controller so I can add about 300 watts of capacity to my solar electric system. It also suffers a bit when the days are short and overcast. I have batteries to get me through the dark times, but they need time to recharge at least twice a week. I hate to add more batteries, because they have a relatively short lifespan (see my other blog entries on battery woes). I don’t need more photovoltaic capacity in the summer, but I definitely need it in winter. I’ll figure out some way to use the excess power in the summer. I’ve been working up some ideas for a while. One of those ideas is to power the refrigerator off the solar during the day, and let it switch back to the grid at night. That would let me use more energy while the panels are generating it, and not put an additional load on my batteries.

I took the Polar Bear Plunge on January 1st. It’s the 2nd time I’ve done it in North Carolina. It was a good time. The water was 49 degrees Fahrenheit (10C) and the air was about the same. The sun was shining and it wasn’t windy, so it was really a nice day, considering it was January 1st.

The little things

I’ve been really busy these past couple of weeks with work. Last weekend the weather was dark and rainy. Today, however, the sky was blue and the sun was shining all day. I took full advantage of the sun’s bounty. I did laundry and hung my clothes out to dry on the clothes line. I baked bread in my SunOven, and I warmed my house with passive solar and a solar air heater. Of course, all of the hot water I use is solar heated.

The solar thermal systems are by far the most cost effective. You may not think of a clothes line as a solar powered appliance, but it really is. Reducing your carbon footprint doesn’t have to be expensive, or technically daunting. My solar oven from SunOven.com is a very simple device, and it works great, as long as you can do your cooking while the sun is shining. Food cooked in the SunOven even tastes better, for some inexplicable reason.

My motivation for writing this came from a story I heard on the radio. I feel very fortunate in that I have the resources to take advantage of renewable energy. I realize that some people just can’t afford to invest in renewables, even though it would probably save them money in the long term. Actually, the best reason for a person with limited income to reduce their dependence on the grid, is that it saves money and offers some peace of mind, knowing that if the power gets shut off, you’ll still have some basic needs covered. It’s also a lot easier to pay those energy bills when they are a whole lot smaller. From a “save the planet” perspective, people who live modest lifestyles are not the biggest concern. Large office buildings offer a much more significant target for real carbon reductions. People who live in 6000 square foot homes, could obviously convert those into apartment buildings and move into something more practical. However, I doubt any of those people are reading my blog.

Based on my experience with energy conservation, there are several things you can do to get started saving some of your hard earned cash without investing anything. You may already be doing some or all of these things, but they are worth mentioning.

1) if you drive, plan and consolidate your trips so you drive less.

2) turn down your thermostat, don’t leave the frig door open, turn off lights, etc., etc. You’ve probably heard most of those tips 99 times.

3) if you don’t use a lot of hot water, you can turn your water heater thermostat down to 120 and save some power.

4) use a clothes line instead of the clothes dryer whenever you can. It may be inconvenient, but if you do it often, you’ll save some real money.

5) water can only get so hot before it turns to steam. If you’re cooking something in boiling water, lower the heat to where it will just barely keep boiling. Put a lid on it, if you can. There are some things that call for a rolling boil, but in my experience, most things cook the same whether the water is boiling fast or slow.

6) turn off your TV when nobody is watching it. Actually, you’d be doing yourself a favor if you left it off most of the time.

7) put your computer to sleep and/or turn off the monitor when it’s not in use during the day. Shut it down at night.

Those things won’t cost you a dime, but they could save you a bundle. If you can make a modest investment, replacing tungsten bulbs with more efficient bulbs will pay off in a year or two, depending on how much you burn your lights, and the bulbs you buy. I have a couple of 7.5W LED bulbs in my kitchen that were an experimental purchase. I’m sure they’ve saved some energy. My kitchen light is the one that is on from the time it gets dark until I go to bed. It is where I spend most of my time when I’m in the house and I’m not working or sleeping. I wish I could say that the LED lights are performing flawlessly. They are probably about 1 year old and one of them has taken to flickering. An LED can last for 100,000 hours of use, but they run on low voltage DC current, so an LED version of an AC bulb (one you’d screw into a standard socket in your home) requires some electronics to convert the AC high voltage power into low voltage DC current. Apparently my bulb is defective, or it was cheaply made. I may bust it open and see if I can repair it. However, the 12V LEDs I’ve been experimenting with will likely replace my ceiling lights. I will have to run wires around the house to connect them to the battery bank that is charged by my solar panels, but once I do that, I’ll have bright, cheery, low voltage lighting that is also highly efficient and will be there for me, even in a power outage.

You might think I’m rich, but I’m not. I live on a very modest income that is well under half the national average. I use the money I save on my energy bills to buy parts, I salvage and fabricate whatever I can, and I do all of the work myself. I do spend money on my solar projects. Of that, there can be no doubt. My recent battery purchase was $400, and I’m afraid those batteries may not pay for themselves before they need to be replaced.

The fastest payback with solar electric systems is to use a grid-tie system where you don’t store anything. You use the energy you generate while you’re generating it. If you generate more than you can use, your electric meter runs backwards, and when the sun goes down, you rely on the grid for your power needs. The problem with that system is that, when the grid goes down, so does your solar production. You have all that potential, but you cannot use it when you need it most.

I’m more of a boyscout than I am a shrewd business person. I want my solar power to provide me with some security against outages. My solar panels charge a bank of batteries and power some nominal loads during the day. At night, I run some lights and computer equipment off the batteries. You lose 20-30 percent of your power when charging batteries, and when the batteries are fully charged, the potential of my solar panels is often underutilized. The advantage is that my system is completely independent of the grid. It’s like a giant uninterruptable power supply (UPS).

Since I have admitted that I’m not the shrewdest business person, I might as well mention that I have taken no tax credits on my investments. I don’t need the government to subsidize my choices. There are some pretty lucrative tax credits to be had, and I don’t blame anyone for taking advantage of them. That is just not my way.

Hurricane Sandy may have been the storm of the century, but there are going to be more like it in the next 5 years. Of that, I am pretty sure. People should be talking to their neighbors about how they’re going to weather the next big storm. A distributed power generation system is much more reliable than a centralized one that relies on miles of wires to deliver power. At least me and my neighbors will have a place to charge their cell phones. It’s too bad all the cell towers will probably go down.

Status update

The pond on August 10, 2011

The summer has certainly been different from our last few summers. The weather is actually¬† more like it used to be about a decade ago, when it seemed like we had a thundershower every day. Although, back then, I don’t recall having so much cloudy weather. The good news is that I’ve hardly needed my new rain collection system. It has been nice having an outdoor shower supplied by rainwater, for rinsing off and cooling down after mowing the grass or working in the yard. I haven’t needed to water the plants, and we’ve been getting enough rain to keep the tank topped off. I don’t need to pipe the overflow anywhere, because both of the ponds are also full. It’s been a long time since the big pond has been full (except immediately after a tropical storm). The frogs are very happy.The pond on August 31, 2012

The photo on the left is of my back yard pond last August (before hurricane Irene blew through). The photo on the right is a recent photo of the pond, which has been filled by normal rainfall, which means the groundwater table has also been replenished, at least to some extent.

The other good news is that I haven’t had to worry about my solar water heater running in overdrive. We’ve had just enough sun to meet 100% of my hot water needs, but I seldom have to worry about the water getting so hot that the system has to shut off (185 degrees F).

Too much hot water!

I’ve had my solar water heating system in operation since May 2011. It works really well. In over a year, I’ve turned my electric water heater on for part of 2 days. Once, we had experienced about 7 heavily overcast days in a row, so I was just running out of hot water. The second time, I had to drain and recharge the collector loop because I didn’t have enough antifreeze in the solution. That means that my electric water heater has been powered up for less than 24 hours in over 400 days. The solar water heater is providing 99.75% of my hot water. I even do some of my laundry in hot water and rinse my dishes in hot water because the heat is free.

solar water heater panel partially covered with a sheetWell, now that summer is upon us, again, I can’t use enough hot water to stay ahead of the sun. The primary tank will reach 185F in a day of full sun. The water is so hot, even with R30 insulation on the tank, it’s heating my utility room.

I can set the pump controller to stop circulating the collector loop once the storage tank reaches the desired temperature, but then the collector gets really hot. It reaches temperatures of 300F, and I am pretty sure that’s not a good thing. So, yesterday I enlisted a friend to help me put a sheet over about two thirds of the panel, to deflect some of the sun’s heat. We had a day of full sun, today, and the sheet worked well at moderating the amount of heat. It’s a good temporary solution, but I’m going to have to work on something more permanent and easy to control. It would be really nice to have an automatic louver system, but I’m not that ambitious, and I’m pretty sure that would cut down on the effectiveness of the panel when I actually need it to work at 100% capacity.

Introduction

solar panels on custom tower

The Solar Tower

This is my first blog post, so let me get started by introducing my tower. I built this tower from square, steel tubing, anchored in steel reinforced concrete. I installed my solar water heating panel and my photovoltaics on the top of the tower, which is oriented to face due south.

The green box holds batteries, a charge controller, and some other electronics for monitoring and controlling the power generation part of the system. There is also a pressure tank for the rain water pumping system in that box.

Mounted below the green box is a 275 gallon water tank that holds rain water that is funneled into it from the gutters on the house. There is a 12 volt, solar powered pump and some plumbing that connect to a couple of spigots where I can connect garden hoses and an outdoor shower for rinsing off after a hard day, working in the sun.

My photovoltaics charge batteries that power some 12 volt equipment in my house and an inverter that provides 110V AC for powering tools, my electric lawn mower, and other things. The batteries also power my water pump, as previously mentioned.

I’ve always got several projects in the works, and I hope to use this blog to document my progress on those projects.