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close this bookThe Biogas/Biofertilizer Business Handbook (Peace Corps, 1982, 186 p.)
close this folderAppendix
View the documentNew ideas
View the documentComposting
View the documentBioinsecticides
View the documentFerrocement
View the documentFacts & Figures
View the documentSources & Resources
View the documentFeasibility Studies
View the documentProblem solving
View the documentVocabulary

Problem solving

How do you get a problem? There is not just one answer to that question. Problems come in different ways. There is no telling when one will appear. But there is a moment when you realize there is a problem.

It is not always enough to know you have a problem. Sometimes it helps to see where it came from. That is not always easy; problems sneak up in different ways.

One Way: You notice something is not quite right. Not the way it should be. The fertilizer from the biogas digester has always increased the quantity and quality of your crops in the past. But not now. It is as though you were using no fertilizer at all. Using the biofertilizer has become a waste of time.

Okay, you know there is a problem. Now that you have it, are you sure what it is?

· Is the fertilizer no good?

· Could it be that you have been using too much fertilizer too often?

· Is the fertilizer being used at the best time in the plant growth cycle?

· Is the digester being overloaded?

· Is the digester sludge left in the aging pond long enough? e Has rain diluted the sludge?

A second way: You open the outlet gate valve on the digester and nothing comes out, even though the digester is full.

· Is the digester so full of solids that the outlet is blocked? How would you find out if that is the problem? If it is a too high percentage of solids what would you do? How did the percentage of solids in the slurry go over the ten percent in the first place? Is the problem the valve, the solids, or how the slurry is prepared? Or is the real problem something else?

A third way: Something has been bothering you for a while. Your five cubic meter family digester is working, producing biogas and fertilizer, but you feel it requires more time and more work than the biogas and fertilizer are worth. It costs more to produce your own gas and fertilizer than it does to buy bottles of pressurized gas and bags of chemical fertilizer. Not every consumer should be a producer. Is the digester temperature 20 degrees centigrade? The biogas bacteria would see that as a problem and not produce much gas. Have you sat down and figured out what would be the best combination of available plant and animal wastes to feed the digester? Maybe you should have joined a biogas business or cooperative instead of building a family digester. Where is the problem?

It is not always easy to decide where the problem is. But that is the important first step. No use solving a symptom of the problem and leaving the problem untouched.

Your first idea may not be your best idea. Go comparison shopping for solutions. Take a good look at several ideas before you choose one. If you want 5.0 cubic meters of biogas every day, the solution is to build a 5.0 or 6.0 cubic meter capacity digester, right? Maybe. Maybe you should start a neighborhood biogas cooperative and own a 25 percent share in a 20 cubic meter system. Maybe you should invest in a biogas business and make enough money to buy all the bottled gas you want.

Making lists is one way to study a problem. Lists can be used to help remember things, but they can also be used to help you think. Lists can help you look at things in different ways. You can list your fuel and fertilizer needs. You say you are not a farmer and you do not need fertilizer. Do you have the land or the desire to build a fish pond? You could list the ways you could sell the fertilizer. You could list your resources: money, skills, organic wastes, and so on. You could list possible solutions: family biogas system, business biogas system, or cooperative biogas system; and under each possible solution you could list what your role (active partner, investor, etc.), costs in time and money, and potential profits might be. Remember that trap of looking at something in only one way.

Be logical. That is a method you have heard about for solving problems. When using logic you pick a direction for your thinking to go in. Then you go step-by-step. You check each step along the way that makes sense. Hopefully you get what you are looking for.

The problem with logic is, in which direction should you go? If you go down the wrong road, logic takes you to the wrong place. If you cannot decide which direction to take, logic will not take you anywhere.

Logically, fresh sludge from a digester looks very watery; you see very little solid matter floating on top of the bucket and very little left in the bucket when you use the sludge to dilute fresh waste going into the digester. Everything is fine until a few months later when biogas production drops off and nothing comes out of the outlet. What your logical eyes did not see was solid matter suspended, floating in the sludge, not much (only about ten percent), but enough to make a difference in time--if the solids are not filtered out of the sludge before it is used to make fresh slurry. Learning to solve problems does not mean learning to be more logical. It means learning to think in different ways. Not always in a straight line.

Sometimes you know where you need to end up. But, it is knowing how to get there that is the problem. Going backwards is sometimes a better way to go. It can save time; it can make a problem a lot easier to solve. Suppose you have two slurry buckets. One holds ten liters. One holds six liters. You need to know where the eight liter line is in the big bucket for when you mix fresh slurry. How can you do it? Do not start by pouring. That may get you going in a useless direction, and you would be wasting a lot of slurry. Picture where you want to end up. Now try to back up one step at a time to see how to get there. (The answer is at the end of this section.)

Sometimes you do not ask a question because it seems stupid, silly, or because you feel it would be embarrassing to ask. Questions such as: Why is biogas bubbling up through the water that the gas storage tank floats in?

Successful problem solvers cannot go around hoping someone else will ask the questions. Asking questions is a good way to find out something. Practice questioning what you read, as well as questioning other people. But before you can ask what you need to know, separate what you know from what you do not know about a situation.

It has been said that two heads are better than one. Then maybe twenty heads are even better. For some problems, it helps to have other people's opinions. Then you can pick and choose among many ideas and maybe even come up with a completely new idea. Before building a biogas system, you might ask all the farmers and fish pond owners you know if they would buy biofertilizer and at what price for both the liquid and the solid kinds.

You would want to know what the local prices of chemical fertilizers are, if they are used much, and if anybody is already using organic fertilizers such as fresh manure (which is a health hazard) or compost. You might find that you have to give the biofertilizer away for free for a few months in order to convince farmers of the fertilizer's quality. But that within one or two growing seasons you can make a profit selling the biofertilizer at a price equal to or less than that of chemical fertilizers of equal value.

You might have questions about biogas system operations that are not answered in this book and cannot be answered even with the help of friends. You could write letters to VITA, Maya Farms, or the groups listed in the International Bio-Energy Directory for their opinions and help. You could ask a nearby Peace Corps Volunteer, if they are working in your country. If they cannot help, they should know where to ask for help.

You want to build a biogas system and you have enough plant and animal waste to feed the size digester you have chosen. The problem is: What is the easiest way to get the waste into the digester? Explain the situation to your friends and see what they suggest. No one friend may have the best solution for your situation. The answer may be a combination of several suggestions. You can pretend to be different people you know and ask imaginary people how they would answer your questions. Whether you are asking real or imaginary people, you will see how different people think differently. The more you do this, the easier it will be to think differently when you need different viewpoints.

There are times when thinking crazy on purpose is a good idea. Not acting crazy, just thinking crazy. Let your mind run wild in different directions. For example: If you decide to go into the biogas business, how could you persuade other people to join you? Whom would you ask? Should the biogas system be a private business or a cooperative? How big should the system be? How should the system be operated? How should the gas and fertilizer be used? How could composting and bioinsecticide be added to a biogas business? Could the waste from a town's market place support a biogas business? How much per kilogram should you pay people to collect water lilies for the digester? Let the possible questions and answers run wild.

Another approach to problems is to find a similar problem to the one you have. It may be a problem you have already solved. It may be a problem that you could solve more easily. In either case, you will get a helpful clue for your thinking, a push in the right direction. Anyone who understands how to build ferrocement water tanks knows how to build strong, inexpensive concrete biogas digesters and the water tanks for gas storage tanks.

In real life, very often the same problem shows up over and over. Sometimes it is disguised so that it does not look the same. If you do not learn from your first solution, you will just keep getting the same problem again and again. That is no way to live. If you have solved one problem having to do with the biogas pipes, think about what you learned; it may help solve a new gas pipe problem. The same is true no matter what the problem is: liquid fertilizer distribution, scum layers, or waste to water slurry ratios. Sometimes what is a help in solving a new problem is not remembering a similar solved problem but remembering a method of problem solving that worked well for you.

There are some problems that are totally confusing. For example: You want a biogas system but do not know where to start; there are so many decisions to be made. You have no idea what the answers are. Not even wrong answers. One big blank. What you need is inspiration. A brand new way of looking at the problem. A little hope. You need to relax and dream about the problem without worrying about it. Sleep on it. Give the problem a night to just roll around in your head without any pressure to find a solution. You might be surprised. The answers, or at least a few important clues, might just appear at the strangest time.

No matter which way you go about solving a problem, try to do it in such a way that the challenge is enjoyable. Many times there are no clear solutions. There may be several possible answers, not just one. It is not always easy to know when you are right. Thinking about thinking can help you get a good start.

The answer to the two buckets problem: You want eight liters in the 10-liter bucket. So two liters have to be subtracted by pouring it into the 6-liter bucket. That is the last step. To know how much two liters are, you must already have four liters in the 6-liter bucket. You can do that by filling the 6-liter bucket from a full 10-liter bucket, pouring out the six liters, and pouring the four liters that are left in the 10-liter bucket into the 6-liter bucket. To complete the solution, pour two more liters from a full 10-liter bucket into the 6-liter bucket that has four liters in it. Now that you have found the eight-liter level, do not forget to mark it. Working backwards can be fun. (This section was adapted from The Book of Think.)