Thoughts on Calculating Solar Power Needs

Written by brad on September 10th, 2010

I’ve talked about planning and calculating solar equipment/batteries before: here and here. Read these first if you’re planning for solar. Now that we have made all our decisions and are living daily with result, I have a few thoughts on the whole calculation business. These thoughts are affected by the realization that you really have to get a generator and that ours will turn on and off automatically as needed.

Why do you need a generator? No matter how well you plan, something could go wrong. A couple of my neighbors discovered this recently when one lightning strike took out both their inverters. If you agree about needing a generator, calculating what you need in the way of solar power should take this into account.

1) You absolutely need enough battery power to last 24 hours. (In three months we have never failed to charge the batteries each day.) I don’t know where they came up with get enough batteries to last three days. It’s nice, but batteries are very expensive.

2) The most important thing to calculate is the continuous average wattage you expect to use. Things that are rarely used like vacuum cleaners really don’t need to be calculated except for a maximum watts at one time calculation.

For us, this is about 450 watts. At night we often creep down to 200 or so watts; never under this. During the day it’s usually between 400 and 500 watts. If the refrigerator is working hard, it can go up to 800 watts or so for awhile.

3) You need to have an idea of the maximum watts you’ll ever expect to need at one time. Inverters are rated by the maximum number of watts they can deliver. Our inverter can deliver 6000 watts. I doubt we’ve ever used 3000 watts at one time. We for sure have used 2000 watts.

4) Plan your system so you don’t go broke running your generator, but also plan your system so you don’t go broke trying to live without a generator.

Other thoughts on solar power-

No one ever talks about this- (I realize it’s probably because it’s a bad idea, nonetheless…) I increasingly feel that a few panels facing east and west would be of value. For us I think 600 watts each direction would be pretty useful. Basically it would extend the number of hours a day you produce power–you start generating power earlier in the day and later into the evening.

I’ve thought a lot about wind energy and I’ve given up on the idea. We have great wind quite often; however, it’s not reliable enough that you could count on it. If you can’t count on it, then you need another plan.

 

Living with off-grid solar power

Written by brad on September 8th, 2010

We’ve been living full time on solar power for three months now. We’ve never had an outage or any trouble at all–good news.

You can generalize about life on off-grid solar power to some extent, but each situation is different and depends on its own environment and equipment. Common to everyone, I think, is that you use as much power as you can during hours of sunlight, and you conserve the rest of the time. We seem to have planned pretty well and so far there’s not been the slightest reason to think we’ll empty our batteries. I very much doubt we have the three days of battery power I planned on, but I have thoughts about why this is OK.

On sunny days, which is to say about 95% if the time,  our batteries are usually fully charged by 10:00 AM to 11:00 AM. For the rest of the day, the solar array is in a stand-by (I’m over simplifying) mode supplying power to the house and keeping the batteries charged until there’s so little sunlight that we’re on batteries until the next day. On cloudy days, it can take until 1:00 or 2:00-ish to fully charge the batteries, and we’re often on battery power before the sun has gone down.

We have never had a day in which the batteries didn’t get fully charged. Note that we have not bought a generator yet. This is especially surprising because it’s been a very rainy year, and there’s been a strong monsoon season. Even on quite cloudy days, I’ve seen 1000 watts or more being produced by our solar array. One starts to think that one could get by without a backup generator.

Either we’ve done really well planning our electrical needs, or we’ve had favorable conditions; I can’t be sure yet.

We have a device from the Xantrex people that lets you monitor the solar equipment from a computer. According to it, we’ve never had less than 65% of battery power available. I am suspicious of this number. Every morning it says 65% remaining. I’ve started watching the battery voltage as perhaps a better guide to how much battery power is remaining. Most mornings it reads in the range of 50.8 to 50.2 volts.

One thing I’ve noticed is the the voltage drops in a decidedly non-linear fashion. It drops quickly from 53 volts (that’s the maximum) to 52 and to 51 volts. After that, it slows down. We often go to bed at say 50.4 volts and find it’s only dropped to 50.3 volts in the morning. This makes it really hard to know how much power we really have in the bank. The manufacturer of our batteries says that 48.4 volts is that halfway point that you’re not supposed to drop below. The Xantrex people say that when they say there’s 50% left, that is the point you’re not supposed to drop below. These two don’t jive. Still working on understanding.

It would be pretty easy to figure things out if I want to just turn off the solar array and watch the power slow run out. I don’t think it’s worth the bother of ending up temporarily out of power – especially since we don’t have a generator to bail us out.

They tell you to plan your system for three days without power. I have ambivalent thoughts regarding this. On the one hand, using this as a guide yielded a pretty good system. On the other hand, it’s misleading. There’s never been a day we did not generate a fair amount of solar power. On the other hand, I think you have to get a generator. If you have to get a generator, then running it once in awhile is probably cheaper than buying enough batteries to last three days.

Do you need a generator? I think that you do if you are living full time in your off the grid home. The main reason is the refrigerator/freezer. I think there’s a fair chance that we will never feel desperate to use a generator. Still, as our neighbors can attest, if your inverter fails you’re in the dark without one. One neighbor has been living on his generator for three or so weeks ow while his inverter is being repaired.

A big concern has become the lightning that is so frequent here — especially during monsoon season. One lightning strike about a quarter a mile away from us took out the inverters of two of our neighbors. It also blew out our cable modem – we were lucky. It seems the phone wires carried the power from the lightning strike to our doorsteps. To combat this, I bought a lightning surge protector for the incoming phone lines. When I installed it, it looked to me like the cable that the phone lines come in on is surrounded with copper. I can’t help but think that the lightning runs along this copper to all the houses in the area and “why isn’t it grounded?” OK, it’s grounded where it comes into our house, but I wish it were grounded further away as well.

All in all, living off the grid for us is no different than on the grid except that if you’re on the grid they tell you to run your appliances at night, and we run ours during the day. Well, there is the fact that our power never goes off. Around here, people living on the grid spend a lot of time cursing the frequent, though usually short, power outages.

[A postscript from karen: From my perspective, there is very little that seems different about living off-grid. That is in large part because of all of Brad’s planning and the purchase of a robust system and a lot of new energy efficient appliances. We really don’t avoid using appliances at night — I am writing this after dark; we use the stove and oven every evening (they are gas but the oven uses some electricity); we watch several hours of TV most evenings (it’s still baseball season, though it’s been a dismal one). The biggest difference to me is that Brad is always fussing with watching the system figures. Oh, one more thing — I don’t feel guilty about standing in front of the refrigerator with the door open since we are using no fossil fuels in doing so. I am looking forward to getting a generator (which we will do soon) but only to have one more level of backup. You can’t have too many backup plans in my book.]

 

Effects on the community [foodchoices]

Written by karen on September 6th, 2010

We’ve looked at how food choices affect our own well-being, so let’s look now at how food choices affect our community.

First and foremost, our collective food choices have an impact on small family farms. In the 100 years or so, there has been a huge move from small family farms to large agribusiness. In 1900, almost 40% of the nation’s population lived on farms. Now, less than 2% does. In the same period, the number of farms has shrunk from 5.7 million to 1.9 million. The average farm size has gone from 146 acres to close to 500 acres. Most notably, large farms produce about 75% of total agricultural output.

Intensive farming or factory farming became popular after World War II with the advent of new chemical fertilizers, pesticides, antibiotics, and lots of government subsidies to encourage high productivity mono-cropping. Some of the advantages of factory farming are higher efficiency and lower food costs. Some of the disadvantages are environmental degradation, public health concerns, a decrease in biodiversity, and animal cruelty.

Some may think that bemoaning the demise of small farms is a hearkening back to days of old and that the modernization of farming is for the nation’s overall benefit. The more I learn about factory farming practices, the more I disagree.

Beyond the big picture outlook, I now have a much keen sense of how an individual purchase decision affects an individual farmer. Like any small business, but more even than most, a farmer who is deriving most of their income from farmer’s markets or CSA purchases depends on individuals in the community. For us, deciding to buy carrots at Safeway vs. the local farm stand seems like a minor trade-off between cost, quality, and convenience. For the farmer, those minor decisions add up to whether they’ll be able to farm again next year.

Having a small farm is a very tough way to make a living. I think I’m a hard worker and a great marketer, and frankly I don’t think I could do it.

In addition to farming, food processing has become very centralized. I recently heard that a post-9/11 threat assessment by the government ranked food processing as one of the greatest areas of vulnerability. (After deciding they couldn’t really do much about it, they apparently stopped talking about it.)

Buying food from small local vendors also helps support the local economy. Most of us probably feel better putting money into the pockets of a small farm family rather than a multinational corporation if we have a choice. And the dollars you spend locally are more likely to stay in the community and make life better for everyone. Again, I have more of a sense of this living where I live now.

Lastly, there are the issues of sustainability and self-sufficiency. I am not personally one who thinks “the end is near,” but the world is an uncertain place. Living out here in the middle of nowhere, I am more aware of how dependent we are on the global distribution chain. The thought of a break in the chain is disconcerting. For a whole variety of reasons, I find it comforting that, at our house, we make our own electricity and have our own small garden. Being somewhat self-sufficient is always empowering. From a community standpoint, I like the idea that we are not totally dependent on outside forces for survival as well. On the short list of things that people really can’t live without, food is up there.

Most importantly, if the local farmers we come to love decide that they can’t farm next year, it’s a loss to all of us. And one that is unlikely to be undone.

For those interested, more reading and local sources in your community are available here.

 

A tale of retail [foodchoices]

Written by karen on August 31st, 2010

Let’s go back a few posts and look at the various retail options we have for buying food.

I’ve already written enough about Wal-Mart, and I imagine that most people have their own thoughts for or against them at this point.

What about the other big chains like Safeway, Kroger’s, Ralphs, etc.? I’ve regularly shopped at all of them at one time or another and used to think that as long as you bought organic foods, it didn’t really matter where you bought them.

The other choices are “specialty” stores with the big three national chains being Whole Foods, Wild Oats, and Trader Joe’s. We always loved shopping at Trader Joe’s when we had one nearby. Their food is fresh, natural, delicious, and a fair amount cheaper than Whole Foods and Wild Oats.

What I didn’t know until recently is that these specialty stores make a real effort to stock ethically produced foods. They look at things like how their suppliers treat their animals and how they address other areas of social responsibility, like the environment and fair trade.

And now that “organic” has become a marketing buzz word, all the larger chains like Safeway, et al (even Wal-Mart)  have organic lines of product. However, the food they sell as organic is still produced in factory farms. While they adhere to the technicalities of organic labeling law in the U.S., they don’t adhere to the spirit of it. (There are a few exceptions like the dairy products from Organic Valley, which are produced ethically on small farms. The also-organic Horizon line, though, is factory farmed with all its horrors. It’s not what many of us would consider “organic.” Without a lot of research, it’s hard to know the difference.)

The bottom line is if you want to avoid factory-farmed foods, avoid the big chains.

There is one other choice, and it’s one I’ve become more familiar with now that I’m thinking more about food and we have no local Trader Joe’s. It’s local food co-ops. These are cooperatives that provide natural, organic, and ethically-produced food. In some towns, there are retail store-based co-ops. (We have one in Bisbee and one in Silver City. Contrary to what I thought, you don’t have to be a “member.”) There are also small informal co-ops. We have one in Portal that we can order from each month. The only drawback is that you have to order in cases, but we’ve found that that is really not a problem. Here is a directory for co-ops. You can also order a lot of organic, non-factory-farmed foods online. For example, most of what we get through our local co-op is available through Amazon at very good prices. The only challenge is that you have to know what you want….and research what brands meet your own considerations for good food choices.

 

Food prices and policy [foodchoices]

Written by karen on August 29th, 2010

Good article in the NYT last Sunday about using policy to improve Americans’ health by influencing food choices. (I have mixed feelings about this. I’m all for free choice, but with the health care system becoming completely unmanageable — whether you favor a public system or an employer/employee-supported one — something needs to be done. I guess I think that as long as the policy is designed to influence choice and not mandate it, it’s a good thing.)

One of the points of the article is that subsidies have created an environment that greatly favors unhealthy fat- and sugar-loaded fast food. Subsidies on corn and soy (used for animal feed and oil) are huge. (Some day someone will explain to me why the people who supposedly stongly favor the market economy favor subsidies.) As a result, in the last 15 years or so, the inflation-adjusted price of a Big Mac has dropped 5.4% while the price of whole fruits and vegetables has risen 17%.

Everytime I see fast food pricing, I’m amazed by how cheap it is. Tacos for $.33? Burgers for under $1? It defies logic.

People are very sensitive about food pricing though. As a friend pointed out to me recently, someone who chooses the cheapest eggs or milk because of a dollar or so difference might easily spend $100 or so on dinner out and a movie. When we buy food at the grocery, we think it should be cheap and often don’t equate price differences with differences in things like health, the environment, or humane treatment of animals.

Milk is milk, and it should be cheap. Or so the thinking goes.

In a lot of ways, this is the same way most Americans view pricing of gasoline and even water. It is as though we have a god-given right to these things being cheap. In all of these cases, it is subsidies that have made the commodities historically cheap. And it seems unlikely that this is sustainable.

Interestingly, in Europe, food, gasoline, and water are all priced at something closer to a real market price (and are much more expensive than they are here). I rarely read about food or the environment (including the above-mentioned NY Times article) where the significant differences in European and American policy aren’t discussed.

Longer term thinking would serve us all well. In the meantime, individual choices do make a difference.

 

Weather or not

Written by karen on August 28th, 2010

Amazing. We found the rain gauge that we thought we’d gotten rid of in the move. When we won this in a bar contest years ago (in Florida), we never thought we’d find it useful. And the rain for yesterday came in at about 1-1/4″.

IMG_0473

 

We’re at the center of it all [foodchoices]

Written by karen on August 26th, 2010

OK, hopefully, we’ve all had time look around their pantries and think a little about food.

Clearly, in the culture we live in, we have many food choices. (I have a keen sense of this having lived in a country where there was much less food choice. Try explaining that in America, there really is no “staple food.”) So why do our food choices matter?

Most obviously, our food choices matter to ourselves. In particular, many of our food choices are made based on:

  1. Personal preference/taste
  2. Convenience/time
  3. Finances
  4. Health

First, we all have things we like and things we don’t like. And for the most part, as adults, we buy food we like (although that is moderated by other considerations like health and perhaps finances).

In my own thinking about food, I’ve come to realize that we sometimes confuse what looks best with what tastes best. Nowadays, food is often engineered to look good. A fair amount of genetic modification work is designed to produce food that withstands mechanical picking and very long times to market and still looks good. (Pringle, 2003)

Organic produce or small farm produce doesn’t always look as good as the colorful (often waxed and gassed) produce you see in chain supermarkets. But it tastes much better. And if you aren’t sure about this, just think about the difference between a tomato from the garden and those bright, beautiful, but tasteless tomatoes at the grocery.

Nothing tastes better than garden tomatoes (Credit: David Steltz)

Nothing tastes better than garden tomatoes (Credit: David Steltz)

Another huge personal consideration regarding food is convenience. Think about fast food. As a nation, we eat tons of it, and yet I don’t think anyone (with the possible exception of my nephews) really think it is superior food. Convenience and finances are a big part of this food choice.

Convenience is also a factor in purchase decisions we make at the grocery. Ever since TV dinners came out, we have been in love with convenient food. But think about the last ready-to-eat boxed meal you bought and popped in the oven. Granted it’s gotten better since the Swanson days, but I still don’t think it measures up as really great food.

But we are a nation on the go and so we often make food choices that don’t measure up in terms of taste or health because of convenience.

Then there is the issue of finances. Can we really afford to make better tasting/healthier/more ethical food choices? Organic food comes to mind — most consider it “better” (healthier, more ethical), but it is more expensive than regular grocery food.

It’s hard to talk about food and finances without talking about Wal-Mart. They have built an incredible empire around low prices. From a sheer marketing and business strategy standpoint, they are a case study worth studying.

But as several books I’ve been reading point out, low prices come at a cost. Food costs what it costs, so why are Wal-Mart’s prices so much lower than everyone else’s?

The answer is that while the costs are the same, Wal-Mart has been successful in passing part of their costs on to folks other than their customers. Here are a few examples of how they do this. First, Wal-Mart is notorious for squeezing their suppliers to cut their prices each and every year. How do they do this? Suppliers make compromises in their own procedures, and they squeeze others further down the channel. This results in things like lower wages and longer hours for workers (especially foreign ones), less adherence to environmental guidelines (more run-off pollution, etc.), and less attention to animal welfare (inhumane conditions, more chemicals to spur production, etc.) Essentially, this passes on costs to those who have no say in the matter — workers, communities, animals. But it does save the consumer money.

Wal-Mart is also notorious for paying their workers less than the competitors. While the numbers are hard to come by, a discrimination case in California brought out some interesting figures. One was that the average non-salaried Wal-Mart worker in California also received over $2,000 in state government assistance (food stamps, welfare, Medicare, etc.).  (Singer and Mason, 2006) So in this case, Wal-Mart is passing on costs to the government. Other grocery chains were so concerned about the downward competitive pressure on pricing that would result from Wal-Mart supercenters moving into to new neighborhoods, that there was a statewide grocery strike in California in 2003-04. Some were concerned that overall movement to Wal-Mart level prices could bankrupt the state (and that was before the current economic crisis).

OK. Enough about Wal-Mart. The bottom line is that someone pays the cost of below-market pricing.

Fortunately, for the vast majority of us, we have the flexibility to choose something other than the lowest cost provider if we want to. The added cost (e.g. $.25 per egg) can be offset against the cost of one or two lattes a week, an extra week of vacation, or some other extra luxury. Most of us live in a comfortable enough situation that these are choices we can make. So we must weigh the benefit of low cost vs. other things like taste, health, and the effects on others. And choice is the whole point here.

So that brings us to the last aspect most of us probably consider in terms of the personal effects of our food choices: health.

When choosing food, we think about things like fat, calories or carbs, chemical additives, GMOs, etc. We try to read the labels. (Future article coming on that.) But it’s all pretty confusing. Organic food — which uses little or no chemicals in its production — seems like a good idea, but is it worth the cost? And do we know what “organic” really means anyway?

For now, let’s just put health on the list and hope our food choices support good health for ourselves and our families. We’ll revisit some of these issues as we proceed.

Exercise of the day: Think about the personal considerations of preference/taste, convenience/time, finances, and health in terms of the food choices you make every day. Rank them. Which is most important to you? Which usually wins out when you put food in your grocery cart? If there is a disconnect, what could change the dynamics at play?

 

Bibliography [foodchoices]

Written by karen on August 26th, 2010

While I’m thinking about it, here is a partial bibliography of some of the reading I’m doing on the whole food thing. It’s annotated with some of my own comments. If you have your own favorite books in this area, feel free to add a comment.


Lappe Moore, Frances and Anna Lappe. Hope’s Edge. New York, NY: Putnam, 2002.

    This book is about a lot more than food. It is a mother-daughter journey around the world to explore issues of food, labor, politics, activism, and more. This is the book that got me thinking about working at our own small local farm.

Nestle, Marion. Food Politics. Berekely, CA: University of California Press, 2002.

    This book is by a former adviser to the federal government of food and nutrition issues documents the influence of the food industry on our food choices.

Pringle, Peter. Food Inc. – Mendel to Monsanto – The Promises and Perils of the Biotech Harvest. New York, NY: Simon & Schuster, 2003.

    This book by an investigative journalist takes a very balanced look at the pros and cons of genetic modification of food. After reading it, I was less concerned about the health implications of GMOs and more concerned about the patent issues that are being raised.

Robbins, John. The Food Revolution. Berkeley, CA: Conari Press, 2001.

Singer, Peter and Jim Mason. The Way We Eat – Why Our Food Choices Matter. Emmaus, PA: Rodale Press, 2006.

    This book takes a look at three different types of family diets and examines the implications of each backed up with a lot of research. has a definite perspective toward the humane treatment of animals, but I would challenge even the most adamant omnivore to read this and not rethink what they eat. This is a thought-provoking book that everyone should read.
 

What food choices do we have? [foodchoices]

Written by karen on August 24th, 2010

In thinking about food choices, a good place to start is where we eat (out at restaurants or at home). Since I’m less interested in restaurants these days, I’m going to focus on home food choices.

Eating at home first entails getting food, whether fully prepared meals or raw ingredients, so let’s look at some options for that. (Click to enlarge.)

Of course, where you shop depends on many factors, some of which I’ll cover in my next post. For store-bought food, it’s also worth thinking about where your food came from before it got to the store. (Again stay tuned for more on that.)

I’m not sure most people think about what “form” they buy their food in, but it turns out that it’s pretty relevant to the effects of our food choices (on ourselves, our community, and the larger world). For example, say you like scalloped potatoes. Do you buy it as:

a) A container of already-made scalloped potatoes from the deli counter or a frozen, ready-to-pop-in-the-oven pan of scalloped potatoes.

b) A box of scalloped potato mix, just add milk and butter.

c) Buy whole potatoes, milk, butter, cheese, and make it from scratch.

Perhaps because I am a contrarian myself, I can start hearing the objections. “I don’t have time.” “I can’t cook.” “I’m in a single person household.” “My kids are picky.” etc. I’ll talk more about these issues in upcoming posts, but for now, I think it’s worth just reflecting on the food we eat. This morning I went into my kitchen and pantry and looked around.  You might do the same, and think about what’s there, where it came from, and how much you know about it.

We think so much about so many things in life… and yet, most of us don’t think that much about the food we eat. What could be more important than food? Not only does it have a profound impact on our own health and well-being, but it also has a huge impact on our community and the larger world.

[Sidenote: If you’ve read this far, please feel free to add comments below or on subsequent posts with your thoughts, questions, objections, etc. I have a pretty diverse group of readers, and while a few of you are probably right here with me, others are thinking “Here goes Karen down one of her weird paths that really doesn’t work for most people.” I’d love to hear your thoughts as I progress through this series, especially since this is in part preparation for a presentation to a group of people not very much like me. Thanks.]

 

I love food [foodchoices]

Written by karen on August 23rd, 2010

[This is the first part of a series of posts about food and why our food choices matter. It is related to a bunch of reading I’m doing and a presentation on these topics that I’ll be making next month. Since it has nothing to do with the ranch, I will be tagging the posts as “foodchoices” so you can choose to read or not.]

I love food. And when we moved here, one of the things I worried about was that there wouldn’t be the kind of food choices I was used to living in a big, diverse city.

Over time though, I’ve come to see that we all have many food choices, no matter where we live. And , in fact, Brad and I are eating better now than we ever have…even in LA.

Why is that? In large part, it’s because of thinking more about the food we eat.

In LA, we typically shopped by the meal. Each night on our way home from work, we stopped at a grocery and bought the main ingredients for our dinner. We also ate out a fair amount, usually one or twice a week.

Here, we need to think a little further ahead. With no local grocery here, we must buy ahead and plan. When we first moved here, we went to the grocery every week or two. Now we go once or twice a month on average, and it is almost always when we have to go to town for some other reason. (Restaurants are in limited supply here as well. There is one restaurant that is open evenings about 10 miles away. We have eaten there once in 20 months and that was when we won a free dinner there.)

Shopping for several weeks of meals forces me to think about what we’re going to eat several weeks out (instead on what we’re going to eat in a couple hours which requires very little planning and results in much less interesting menus).

Stay tuned for the next installment…food choices we have.