We should be able to buy solar equipment for $1 a watt that harvests 80% of the sunlight available. Big Energy is happy that it costs $7 a watt to install solar panels or solar power plants that deliver less than 15%. Companies make huge profits selling fossil energy year after year. And it’s easy to tax consumers for the fossil energy they use.  Pollution? Climate change?  Future for kids? Those are our problems!

The director of a public library asked me if she should engage an energy service company to install a large array of photovoltaic panels on and around the building. The company offered to finance a $1 million, 144 kilowatt system and bill the library 90% of what the utility would charge for the power solar displaces over 20 years. The library would pay less for electricity and become a billboard for sustainability. I told her that it was a good deal for the library. It’s also great for project designers, management, manufacturers, construction workers and investors. But for our kids, who have to pay back the subsidies involved (probably over $500,000) with interest, it’s not so great.

What about the library’s carbon footprint? There will be less pollution from the coal burning power plant that supplies electricity but it will take three to five years for the PV array to replace the energy embedded in the PV equipment and project construction. This PV array will then deliver clean power for two decades, which is good. But at what cost? Our government supports Big Energy’s fossil exploits through tax incentives, military actions, and overlooking pollution costs so it’s appropriate to subsidize installing renewable energy equipment. My problem is with how bureaucrats foster technologies that will forever require subsidies because they perform poorly. We are not doing what it will take to transition from our past robust economy, fired by cheap fossil fuels, to a vibrant, modest future that slowly replaces more expensive fossil carbon with ever more powerful renewable energy products.

Like personal computers, solar equipment today should be inexpensive and deliver huge value. And should replace the embedded energy in a few months, not three to five years. Today’s solar options are like the government subsidy program that depletes fossil energy to produce an equivalent amount of ethanol from food grade corn, wasting both the fuel and food! Fancy PV panels on roofs convert about 12% of the sunlight that hits them into electricity but, since they don’t move, they deliver rated power around noon, if they are properly tilted toward the equator, and no cell is in a shadow. The same panels on trackers that follow the sun would generate at least 40% more power. But both static and tracking arrays throw away 88% of the solar energy available. These huge investments waste most of the clean energy!

It takes substantial structures to hold the PV panels so storms don’t damage them. The PV modules themselves have frames that protect the edges of the glass on which the PV cells are mounted. It’s easy to reconfigure the same materials into a parabolic dish solar collector that uses glass mirrors to reflect sunlight hitting the large area of mirrors to a small receiver. The ratio of mirror to the active area of the receiver can easily be 1,000 to one. That means 1,000 one foot square mirrors illuminate a square foot of CPV cells that accept concentrated radiation. There are a few varieties of these cells available that convert from 20 to 38% of the sunlight into electric power: much more efficient than those used in common PV panels. CPV cells work best when cool so the cooling fluid is not useful for heating or powering an absorption air conditioner (that uses heat to generate cooling).

Sunlight through a prism has many colors but about half the energy is invisible because it is in the infrared, IR, part of the spectrum. Solar cells can’t utilize IR well but “hot” mirror coatings that reflect IR radiation and transmit light could direct half the energy for another use. High performance solar cells can be mated to secondary concentrator optical elements that reflect IR and distribute the visible radiation to best advantage. With this kind of receiver it would be easier to cool the cells (because the IR energy would not be involved) and the IR energy can be harvested separately in a boiler, at a temperature independent of the CPV module. This means a 1,000 square foot concentrator with a very small receiver (the size of a waste basket) should be able to deliver 20 to 30 kilowatts of electricity, along with enough steam for cooling a small building, making hot water for showers, space, laundry, and for cooking or sterilizing and many other possibilities. One would need readily available auxiliary equipment to handle these additional tasks.

A target cost for such a system? No more than $1 per watt of electricity, no charge for heat. Such a system might cost $20,000 to $30,000 but a “sell” price would probably be higher unless available as a kit. Cost of installation would depend on site characteristics and related permitting and construction costs. Five such units, that one day could be installed for less than a quarter of the above library’s proposed system would deliver more electricity. They would also provide all the cooling and most of the heating (the sun doesn’t shine some weeks in winter). The investment in auxiliaries should be less than the cost to heat and cool for three years. The only part I’m sure of is the tracking concentrator: those parts cost less than half the projected total. Others will have to make the CPV cells, secondary optics and combine them into a receiver module. The boiler portion that in an hour delivers the energy equivalent of burning a gallon of fuel oil (125,000 Btu) in full sun, and insulated steam lines, should cost under $1,000.

In the solar arena, Big Energy and government seem like mainframe computer folks at the dawn of desktop computing: “We are developing all the renewable energy delivery systems you’ll ever need. Trust us. No one will ever want their own personal energy system!”

As I’ll cover next time, very expensive fields of heliostats around power towers and huge fields of parabolic trough collectors in deserts have a hard time exporting more than 15% of the sunlight available. Wasting 85% is “state of the art” but it doesn’t have to be our future.

Off topic: a photo of this year’s forsythia that don’t always flower as nicely, behind some of next year’s wood:  http://screencast.com/t/YTYwOTE5ODI

Pond bubbling equipment has been put away, maple trees are leafing, next year’s firewood is drying, vegetable seedlings are growing and asparagus are shooting up. Spring is progressing nicely!  We made only three pints of maple syrup from our tree this season instead of our usual two or three quarts because the weather turned warm, and rarely went below freezing. Many of our neighbors around upstate New York and Vermont have reported similar low yields. But the warm weather has made collecting firewood a pleasure. I’ve gathered about five cords and have put away three, with one more cord to cut. With three cords left from last year, we already have enough for the coming heating season. I want to cut down the trees that have grown up and now shade our greenhouse without bothering the honey bees that live in this grove. Rather, I don’t want them to bother me!  So on the next very cold day I’ll drop everything and finish getting our wood.

Self reliance has rewards and setbacks, but, as long as we’re healthy, fixing things that break is part of living. Here are a few things on my list:

• This winter heavy snows and ice collapsed one edge of the long bridge that crosses one end of our pond. The fasteners that sheared off on one side will have to be replaced. It will take warm weather, and a warm pond, before it will be fun to figure out how to jack up the 16 sections and put in bolts instead of screws.
• The tractor’s cooling system leaks so I have to add a quart or two of water/antifreeze before heading out. It looks like the seal on the water pump needs replacing so that shouldn’t take too long.
• Heavy snows knocked down most of the deer fences around one of our gardens, but they still do their job. Making them presentable, though, and good for peas to climb, will require some effort.
• The outlet to our gray water system froze a few times this past winter and will need an insulated structure before next winter built to allow the sinks, showers and laundry to function well.
• The axes and mauls I use for working wood need new handles. I replaced one last night by carving the replacement fiberglass core, polypropylene sheathed one so it fit into the head and then filling the gaps with epoxy. To prevent the runny mixture from leaking out, I used hot melt adhesive around the base and it worked well.
• Our well water pump leaks in air so it needs work. I’ve run the wires so that our photovoltaic system can run the pump but I have to dig down through seven feet of fill to repair the pipe, and at the same time build a conduit to lead away water that flows through the basement. We had a great drainage system that a very large willow was happy to use as its water supply and has now filled all the four inch diameter pipes with roots. But it gives us wonderful shade and attracts lots of interesting birds.

In 1985 (I just checked the date written in the concrete foundation) we put up a polar column to support one end of a large tracking solar collector. Government officials didn’t want us building this government funded effort in our backyard, so they had us put it up at their facility, more than 2,000 miles away.  This 80 foot tall open lattice tower, just south of our greenhouse, attracts lots of birds who dropped seeds and now a variety of trees grow under and around the tower. Over the years, these primarily wild cherry trees shade the greenhouse through the middle of the day – so it doesn’t overheat. But it also diminishes how much food we can grow. It’s fine where there are no leaves on the trees, but not good when leaves provide too much shade. Many of these trees have trunks over six inches in diameter and will make great firewood. The branches make good structures for tomatoes and beans to climb up.

In 1987 we erected the hybrid solar power system in the southwest and tested it the following year. It delivered around 45 kilowatts of electric power and utilized sunlight alone or burned fuel oil in a boiler to supplement the sun.  It was the first large two axes tracking solar collector ever built, and is still the largest put up in the western hemisphere. This first prototype did have its share of problems with both the collector, the steam engine and the fossil fueled boiler but after working through these, the system operated as designed. Our plans for building less expensive and much more powerful equipment never got off the ground because bureaucrats chose to fund only parabolic dishes that were mated to Stirling engines. Our more than thirty submissions (requiring many hours of work, each) to government programs were turned down. That would have been justified if alternative program succeeded making better equipment but that never happened.

Over the next weeks I plan to cover some topics like solar technologies, EROEI (energy returned on energy invested – or energy profit ratio) and how we may have to approach living so more people can live well, especially as fossil fuels become depleted. Probably only folks who live off-grid would purchase solar power systems. Very few others would invest in solar technologies without substantial government subsidies. That’s because PV panels, thermal collectors, parabolic trough and central receiver solar power systems are expensive and perform poorly relative to better solar options and those that use highly concentrated fuels sequestered underground. Big Energy likes it this way because they benefit by our burning what they provide today. Why conserve for our grandkids?  At some point, people will realize that living a good life today does not have to diminish living in the future. Personal energy systems can empower individuals similar to how desk and laptop computing did.

Next time I’ll describe different solar options available for homes, and for power plants along with some of their characteristics.

Our greenhouse is our most productive garden. We harvest produce every month of the year and raise a few thousand seedlings there until they are ready to set outdoors. It’s fairly large, 20 by 50 feet, attached to the south side of a passive solar heated building that also receives heat only from sunlight. It has only a single pitch of glazing that we recently raised its peak from 12 to 16 feet because it wasn’t steep enough to shed snow. If snow builds up on the glazing, it’s dark inside and would go below freezing for parts of three months. We live in the northeast about 150 miles from Canada and outdoor temperatures often go well below zero. Now that it efficiently sheds snow, it only approaches freezing during December and January, and the first week, or so, of February.  It’s glazed with a triple wall polycarbonate product, 4 by 20 foot sheets, which has worked very well for over 20 years and still has some life left. We had to turn it upside down two years ago because large hail popped 20 or 30 holes in each of the 12 sheets that prevented the snow from sliding off what is now the bottom. See photo:  http://screencast.com/t/OGIzODQ4MjUt

The secret of successful passively heated buildings is thermal storage that works. You don’t want space to get too hot in summer, and you want it to stay warm through long nights in winter. We’ve put 26 of water-filled tanks, each holding about 50 gallons, along the north side of the greenhouse, with a few each on the east and west sides that start out as clear one foot diameter tubes, 10 feet high. It doesn’t take long for them to grow algae so they soon take on hues of green and yellow. We also have a large, open tank of the same material that holds 500 gallons that we use for watering.  We started out with a lot fewer tanks of water and kept adding more until we ran out of room. It’s working pretty well with it never going below freezing at ground level from early February into December. We harvested our last peppers and tomatoes just before the holidays this past year. See photo: http://screencast.com/t/ZjlkNjdjM2

Ventilation in a greenhouse is also very important. We keep the entrance door in the west wall open most days, starting in March, and never close it from April until October, unless outdoor temperatures go below freezing. We have a large vent with a 12 foot long, by four foot wide opening at the peak of the greenhouse that we keep open from May through September. The constant breeze where we live (on a hill) prevents it from ever getting too hot inside.

One has to water inside every day that there is sun – and even on some cloudy days if plants start to droop. I’ve tried different approaches for doing this automatically, with timers, but the water we use that comes directly from our pond quickly clogs filters, leaky hose and sprayers. I’ve found it easier to water by hand with hose that sprays, and clean it when required. The ten minutes it takes to water all the beds allows me to check how everything is doing and an opportunity to harvest dinner.

Getting the correct mix of plants growing is a challenge. Many plants, like kale, Swiss chard, arugula, oregano, thyme, parsley and other herbs grow year round and only rarely have to be replaced. We grow biennials in order for them to produce seeds the second year for planting outdoors: beets, cabbage, and carrots. We always have Asian greens and salad crops growing year round and these seem to do well even except maybe the coldest weeks, but they sprout new leaves when it warms up. When blight killed all our tomatoes before producing any for canning, our eight greenhouse tomato plants kept us with plenty for sandwiches and salads from June into December. Our eight each pepper and cucumber plants also produced more fruit over eight months than dozens more did outdoors this past year but would not under better conditions.

One of the neatest greenhouse activities? A wading pool for kids. Any sunny day, even in December or January, a shallow pool can get up to 80 degrees and splashing water can’t hurt anything in a greenhouse. A hot tub would be another possibility that we’ve never had time to investigate. But it could easily be heated with sunlight and help keep plants from freezing.

Other benefits? It’s a great place to work in when it’s cold, windy or raining outside. There’s plenty of light during the day and it’s remarkable how warm it gets even in January when the sun shines. It’s also great for drying seeds, gourds, small amounts of wood for tool handles, woodworking, and making baskets. Our greenhouse has 11 open webbed aluminum trusses that have lots of opportunities for hanging things. An open lattice tower is suspended on its side and is now holding 25 flats of growing plants. Within a month, at least that many more will be strewn about every open surface, including paths, until they get planted in outdoor gardens. In the photo above, tomatoes are growing through this open “bench”.

A greenhouse is also a great place for snakes to hibernate. Since our greenhouse glazing is low on the east side, the beds on that side have up to three and a half feet of wall so you can walk between them without bumping your head on the trusses. Snakes like to hide there and come out when it’s sunny. Although they keep the larger insects and slugs at bay, I have to spray soapy water to keep aphids at bay a few times in spring until the lady beetles take over.

Downsides? The slope of our glazing runs into a raised bed that helps insulate the south wall. Deep snow piles up there and must be shoveled away to make room for more snow to slide down the glazing. I had to do this only twice this past season. Also, you have to keep trapping rodents because they quickly learn that there is always food available. We use live traps so we don’t hurt any of our snakes. You also have to catch any larger critters like opossums and raccoons  if they learn that there is usually food through the open door. Adding a screen door blocks too much air but a door made out of fencing would work – if it comes to that.

Top 10 Tools for Working Wood

This is not about making furniture but about tools for putting away enough wood to last another year. Tools promote philosophical values so my set of tools require exercise, minimize fossil carbon use, and offer opportunities to day dream and think. Carting home many tons of wood takes time but is quite enjoyable when spring is breaking, peepers are chirping, and plants are budding. Much available wood falls in swamps where tractors can’t go. It has to be cut up into portable pieces. A huge oak tree fell down last year and we’ve burned all but the three foot diameter trunk. This spring’s project has been cutting it into 14 inch wide wheels and rolling them the few hundred feet to a field where the tractor and trailer can go without sinking. The sections that have a fork don’t roll and have to be split into pieces that can be portaged. There’s time to think and listen between trips so I’d rather work wood than jog on a highway. So here are ten firewood tools in order of increasing importance:

10. Gas Burning Chainsaw: probably the most powerful tool for working wood ever invented. They come in many sizes but all make noise, typically lots of it. Twenty gallons of gasoline, a quart of oil and a few gallons of bar oil for lubricating the chain that does the cutting enabled two people with a chainsaw to build a cabin in a remote place in six months. It probably would have taken a year with a hand saw, a hammer and a chisel. Making shakes for the roof required a froe, but that’s another story. I hope this will be the last year we have to use this kind of saw where an extension cord doesn’t reach.

9. Diesel Tractor: great for pulling trailer loads of wood weighing up to a ton across wet fields. Each trip replaces up to 30 using a wheelbarrow, a hand cart or pulling limbs along the ground. Depending on conditions, you have to use chains on the front and rear tractors tires and lightly load the trailer to prevent getting stuck in mud – that would take an inappropriate amount of time to remedy.

8. Ax: effectively cuts off branches up to three inches in diameter in a single, diagonal stroke. Also very good at splitting compliant logs cut to stove fuel lengths. The momentum stored as the working end picks up speed can become a problem if it misses its target. I once split my head open when the butt end of an ax caught on a small branch overhead.

7. Folding saw: a hand-saw that has a handle as long as the blade that protects the very sharp teeth (and your skin) when closed upon itself. The blade is thicker than the one used in a bow saw so it doesn’t bend when pushing it forward for another cutting stroke. They are great for trimming larger branches on trees because they are light, quiet and very effective, even when you have to prune fruit trees while perched high in a tree. Bow saws are too clumsy for this work. On long distance hikes I bring a very small version for cutting firewood.

6. Hatchet: great for splitting straight-grained wood for kindling. Also an appropriate tool for quickly removing small branches from downed trees. Inappropriate for pruning. Never put your other hand anywhere near the chopping block – my uncle lost a thumb while splitting wood for kindling.

5. Electric Tractor: a developing resource. We can charge our electric tractors using sunlight but do not yet have a matching trailer appropriate for hauling wood. We also need an inverter that converts the 36 volts battery bank into AC for running an electric chainsaw.

4. Electric Chainsaw: a less powerful version of the gas burning variety. We reduce long lengths of wood carted to our woodshed to appropriate lengths with two sizes of these quieter tools. They use the same bar oil and set of files that the gas powered version require. Every day you cut wood you need to sharpen the chain links that do the cutting using a round file. Every five days of cutting you use a small flat file to shorten the tang that establishes the depth of cut so that it makes shavings and not sawdust.

3. Lopper: a limb cutter that has two long handles. Nothing cuts brush as well as a lopper. Capturing a limb between the blade and anvil portion doesn’t allow it to move away. The long handles allow reaching into thickets, including ones with thorns like rose and blackberry brambles, without sacrificing too much blood. It’s best to clear limbs and brush away from trunks or downed limbs before using a chainsaw. It’s tempting to use a chainsaw for clearing small branches but these can easily get pulled into the guard, deflect the blade, or trap it requiring potentially dangerous recovery measures. It’s safest to use chainsaws only for cutting larger diameter stock and use more controllable hand tools for the small stuff.

2. Maul and Wedges:  use the sharp end of the maul for splitting wood directly and the other for pounding in wedges that can split even the most ornery pieces. You need at least two wedges because some wood, usually with large knots can completely bury a wedge without splitting apart. Using a second wedge, and even a third, to open up cracks emanating from the first usually frees them all. There have been a few elm chunks, though, where only judicious use of a saw released the wedge.

1. Bow Saw: a thin wood-cutting blade pulled taught by a frame forming a “Dee”. Like a hacksaw, tension on the blade permits using a skinny strip of steel to minimize kerf, the amount of wood removed to allow the blade to cut the log or branch. The teeth are slightly bent alternately left and right so that they remove enough wood so the rest of the blade doesn’t rub the sides of the cut. If the opening starts to close, it’s time to remove the saw and start cutting from the other side. If you had only one tool for processing wood, a bow saw would be ideal. It doesn’t use many resources, except elbow grease, and cuts quickly, without requiring undo effort. You would be limited to branches that can fit inside the stove without splitting – but these are the easiest to cut and carry. The blades are hardened and stay sharp for a very long time. And you don’t need hearing protection.