Sunday, September 18, 2016

State of the Farm, September 2016

It's September, now. The drought continues.

Remember when I said the larger plants-- the trees, grapes, etc.-- seem to be weathering it okay so far? Well, "so far" isn't so far anymore.

Two things have occurred.

First, of course, is though we've had some rain the drought continues. Some of the trees are showing stress. These are trees such as cherries and some of the pears. One pear in particular has gone completely yellow and is dropping its leaves a month early. We're hopeful that the trees that are doing this are just giving up the summer and not giving up the ghost. We won't know until spring.

Trees have a blessing and a curse: they reach deep so drought takes longer to reach them. But when the deep water recedes it takes a long time to get it back.

I had been hoping that we'd have enough rain to catch up with the loss before the trees felt it. It didn't work that way. Many of the trees are okay depending on species and location-- all of the espalier look okay, regardless of type. I don't know if this is location or the nature of how trees are trimmed during the process.

I didn't anticipate the other problem we've had.

The thing is, we're not alone in the drought. All of the wild animal life are experiencing the same thing. Many birds are now gathering for southern migration-- not exactly early but they are certainly not lingering. About two weeks ago the Marechal fochs were a week from harvest. I came home and every grape was gone.

They were plucked directly from the vine without a wasted fruit. We've always had a little competition from the turkeys and the wasps. I rebuilt the arbor to discourage the turkeys. It worked pretty well though they still menaced the grapes on the surrounding fence. But turkeys leave a lot of debris and torn leaves around. So this wasn't them.

Wasps, too, like to get the grapes. Often, I've been harvesting grapes in a cloud of yellow jackets. Not stung. Yet.

But wasps eat around the seeds and leave the skin behind. These were plucked cleanly.

I think it was small, migratory birds that cleaned me out. Birds desperate enough to eat anything.

About a week after that, the Concords started scenting the air. The birds didn't target them yet. I don't know why. Perhaps the birds that took the M/F were already gone south. Or perhaps the Concords were less visible or didn't interest them. No idea.

But the hornets figured out there were good things to eat.

The Concords were a week early but I decided in favor of an early harvest against no harvest at all. So, that night, I harvested the vine by flashlight. (Yellow jackets I can bluff. Hornets have no mercy.) So we have about fifteen pounds of just-prior-to-full ripeness Concord grapes in the freezer downstairs.

A couple of years ago I spoke a little about making a drinkable Concord wine. (See here.) I can now do it pretty predictably. I'll tell you my secrets:
  1. Do not use the skins. I know Concord wines are supposed to be reds and reds are fermented with the skins. But don't. If you use both the skins and the juice, whatever chemicals in Concord grapes that turns Concord wine into kerosene gets concentrated. You can use the grapes for a good false wine but that's it.
  2. Use twice as much pectinase as any recipe calls for. Three times if you want. I don't know if there is an upper limit. Pectin is the protein that gels jellies. You add the pectinase to break it apart. I don't know if the pectin proteins are part of the dreaded Kerosene Element or if it's a protein close enough it, too, is destroyed by the pectinase. But if you don't use enough you will regret it.
  3. Filter, wait for settle, filter. Concord sediment is not your friend.
  4. I've been getting in the habit of letting the final rack (siphoning the wine off the sediment) just sit for a few months. Initially, I did it by accident because I had too much to do and bottling is a chore. But it seems to help.
  5. Wait a minimum three years before you claim victory. It takes about that long for the keresenes to break apart.
The last act of farming for the summer was the changing of the canopy.

We have a polyethylene cover greenhouse. Essentially, it's a steel hoop frame over which we put two polyethylene sheets. Then, we have an electrical inflator that pushes air between them, giving us insulation. In it, we grow bananas, papayas, tomatoes, broccoli, strawberries-- well, you get the idea.

The problem with polyethylene is that it breaks down over time under the UV light of the sun. So every four years or so we have to replace the sheet before winter. To have it break apart during winter would be catastrophe.

This involves pulling off  the old sheets to be recycled in some way and then pulling over the new sheets. The roll holding both sheets is about 200 pounds. Pull the sheets over without damaging them is a chore we put off as long as possible.

We did it yesterday. The pictures are above. You can see the banana trees fairly easily in the upper picture. There's also a bush roughly in the middle that's a strawberry guava. Behind the greenery are the other fruit trees and the aquaponics. The lower picture shows the finished product, all nicely inflated. The excess will be trimmed and used in other projects.

That's it for the year. We're looking into irrigation pipe for next year and figuring out how to make the farm a veritable killing field for caterpillars. The town is thinking we're going to have these conditions for the rest of the calendar year.

I hope not.

Sunday, September 11, 2016

A Solar Experiment

It is done.

The project I've been working on over the summer has been completed. That's it to the side there. The dehydrator itself, the area where the fruits, vegetables, etc. are actually dried is the big box. The long thing is the heat collector. The box is about 4.5 feet wide and three feet high. The collector is three feet wide and eight feet long.

Why so big? you might ask.

Therein lies a tale.

We try to live within our means. By this I don't just mean we live within a monetary budget. I mean we try to grow as much of our own food as we can, consume as little outside energy as we can, reuse materials where possible. We have old cars and an old house. There is an ecological component to this but mostly it's because we're cheap as hell.

About four years ago we committed to put up the money to buy solar panels for our house. We bought them so we own the energy that comes in and own what are called SRECs (Solar Renewable Energy Certificates) that come along with it. (See the link to describe what they are.) This means that no only is our utility bill tiny but that we can sell the SRECs at a profit. In the last few years the SRECs have paid for the energy cost of our greenhouse.

This makes me very happy.

But we live in New England. While it's all well and good that we have covered our electrical energy budget, we still burn a lot of energy to heat the house over the winter. We shifted from oil to gas a few years ago but I'm not terribly sanguine about using gas, either. It's low cost is artificial at the moment and it's not doing the planet any favors. So I've been casting about for some way of handling the cost of heating.

We've done most of the normal things: insulate the attic. I built inserts for the old windows to use in the winter that cut heat loss through the glass. But that works on the efficiency of heat loss but doesn't address heat production. We heat a fair amount with wood. That's nice because it's burning recent carbon into the atmosphere rather than fossil carbon but it's still carbon.

I kept coming back to the greenhouse: hot as a jungle in the direct sunlight even when it's twelve below outside. Clearly, solar heating has possibilities.

We couldn't pipe the heat back to the house. The distance was too great to do it efficiently. That meant whatever we did had to happen at the house itself.

Our house is what's called a front entrance colonial. Two stories tall, flat front with a doorway in the center. When the house was built (as a speakeasy brother but that's another story) it had a full sized porch but over the years the porch rotted away and was removed. Now there is just an entrance porch to the door.
Solar panels have two very curious features with regard to snow. 1) They tend to warm so snow slides off easily and 2) they're slick so the snow slides off fast.

We have an avalanche after every snowfall.

This meant a couple of tons plunged down on whatever was below it-- be it bushes, porch or bystander-- all at once. The bushes look terrible every spring and after the first couple of snows, it's a packed glacier. The front entrance becomes unusable and we do all our comings and goings from the side entrance.

Clearly, we need a porch so we can use the front entrance in the winter and keep from eventually destroying any structure in the front of the house. It would have to have a metal roof, too, to handle the impact.

Metal roofs get hot in the sun. Hmm... Could I kill two birds with one stone? Could a metal roof absorb enough heat to supplement the heating of the house?

I did a little research and found a few designs. Here is a general design for a solar space heating system.  Here is one that uses metal roofing coupled with a liquid heat transfer fluid.

One of the critical features of heat transfer is the nature of the fluid used. Most heat transfer systems use some liquid for heat transfer-- propylene glycol is one. It's related the ethylene glycol used in in your car radiator except it's not toxic. Water can be used-- not up here in the Frozen North but it's commonly used in the south. Brine. Etc.

I was interested in using air as the fluid. Air isn't as efficient as liquid but it has the virtue that it is free, abundant and if it leaks there's no mess. (See here and here.)  The porch would be about thirty feet long and about ten feet wide-- three hundred square feet of potential heat collection. Even a fairly modest heat transfer would provide some significant BTUs.

So we discussed the whole process. The idea of building a large porch with a metal roof was somewhat daunting. The idea of building one with untested technology was even more so. Besides, even if we built a good collector, how would it transfer heat to the house? (A problem I'm still wrestling with.)

We decided to run an experiment.

We had wanted a solar dehydrator for a long time and I'd worked over several designs. I'd come up with the idea of a dehydrator that could run on electricity or solar. That way we could run one in the winter as well as in the summer. I hadn't built it mainly because of time and because I hadn't come up with a building technique that satisfied me. Building with wood is fine but wood is heavy for a structure to bring in and take out all the time.

We married the experiment to the solar dehydrator-- giving up the idea of double duty in favor of seeing if the porch idea would work.

The dehydrator is in three parts. The collector, the box and the support. The support was easy so we'll neglect it.

The collector is a frame box with a top of galvanized steel painted black. The back is insulated with two inches of foam.

Why that design? you ask. Isn't it better to have a clear front and capture the energy that way?

Well, yes. That is far more efficient in terms of energy collection.. You get double the effect. No only does the light come in and heat the black back, the re-radiation of infrared is captured by the transparent glazing. (Not unlike global warming. Hence, the "greenhouse effect.") But remember, this experiment has to also emulate being able to take a high impact snow load. There aren't any glazings I know of that will take the avalanche.

The box serves as both dehydrating chamber and chimney. The air comes in from the bottom of the collector, passes into the box and exits out the top.

We put it together today and it's now standing out in front of our house infuriating our neighbors and lowering our property values. Hey. We own the place so who cares?

I've instrumented the box and collector. We're getting good heating inside the collector-- up to about 140 F. I'm not so please at the heat transfer between the collector and the box. I'm getting between 15 and 20 degrees above ambient. Right now it's passive but I think a small muffin fan might help. It's also still pretty hot outside so the heat differential between the box and collector isn't as great as it could be in winter. Be interesting to see hat happens to the box temperature when ambient is below freezing.

But the building is accomplished and the experiment has begun. I'll be taking regular measurements over the winter to see if the experiment is successful.