Generating your own electricity - The Missing Link

Solar and Wind are typical but not complete choices

Every day more and more people are choosing to become energy independent and less dependent on the electrical grid. Even those who choose to remain connected to the grid (Grid Tied), are opting to add some form of alternative energy to reduce their utility bills and become less dependent on the electrical grid. Some are choosing to completely disconnect from the electrical grid, or may not even have access to an electrical grid. Today, Solar Photovoltaic (PV) panels and/or Wind turbines are becoming a primary choice as an alternative energy source. Solar and Wind energy is quickly becoming more cost effective than coal and natural gas that even the utility providers are using these forms of alternative energy to power or supplement the electrical grid. For those choosing to utilize alternative energy systems to generate their own power, they have traditionally had three options; Solar (PV), Wind Turbine, or a Hybrid Solar/Wind configuration. To a less extent, Micro-Hydro is also a viable option but is very site specific and requires a steady year-round source of water and flow such as a river, stream, or spring,

Solar (PV): The use of Solar Photovoltaic Panels (PV) to generate electricity. The size and number of PV panels in the solar array is dependent on several factors including; Geography, available space, power requirements and of course, budget.  A 5KW solar system installed in Arizona will be different than a 5KW system installed in the inland NW due to the different amount of solar energy available each day in each respective region.  More panels will be required in regions where sunlight is more limited to capture more sunlight during more limited sunlight period. This also translates to higher system costs in areas of reduced solar energy in higher latitudes. Thus a system designed for the inland Northwest must take into consideration the limited number of hours of sunlight per day, the extended periods of limited sunlight in the winter months and storage capacity of the battery bank to store sufficient power through these periods.  This is a much different consideration than that of the similar size system installed in Arizona which has far more hours of sunlight and very few days of limited sunlight all year.

US Solar KWh Per Day by Month

Wind Turbine: Wind Turbines are another popular choice for generating electricity and unlike solar energy, can generate electricity anytime day or night, as long as there is a minimal amount of wind, typically around 5-7 mph. A single wind turbine can generate as much or more than a large solar panel array. As with solar, there are several factors that must be taken into account when considering a wind power system including; geography, site condition (terrain, obstructions, trees, etc.), power requirements and budget.  It is interesting to note that the areas that are generally more suitable for wind, also are areas that are not optimal for solar. For example, in the above solar example for the inland Northwest, where the solar system must be built to accommodate lower available periods of sunlight, this same area is often more suitable for wind power with more areas of higher average wind speeds.

US Average Wind Speeds

Solar and Wind Turbine (Hybrid): If you were to plot the available solar energy per day by month for almost any geography you would see that the highest periods of solar energy are in the summer months and the lowest are in the winter months. If you were to compare that to a plot of average wind speeds per month you would see the opposite; that the lower wind speeds were generally in the summer months and the higher wind speeds were in the winter months.  If you overlaid these two graphs, you would see that wind energy and solar energy generally complement each other.  In a 'Hybrid' system which would include both solar and a wind turbine, each system would generally compliment the other. In the winter months where there is less available sunlight, there would generally be more wind to power the wind turbine. In the summer when there is generally less wind there would be more solar power available.  Thus, a hybrid system could be used with a smaller solar component and smaller wind component so that the combined system will generate the required power on a more continuous basis.  Today, hybrid systems are becoming more popular because of these synergies.

Hybrid Solar / Wind Energy by Month

While each of the above systems can be designed and configured to meet almost any electrical power requirements from a weekend cabin, to a large household with all of the standard amenities and electrical appliances, they all have a major limitation. Solar systems do not generate any power at night and times of no sunlight. Wind Generators must have a minimum wind speed to generate power (often above 7 mph). So even when using a Hybrid system, there will be times when neither the solar panels nor a wind turbine is generating any electrical power.

The most important component to any off grid power system is the battery storage component. Any power generated by the solar panels, wind turbine, or any other energy source are stored in the battery bank in the form of Direct-Current (DC) power.  This DC power is then converted to AC power through an inverter. It is this AC power that runs our standard electrical appliances.  The battery bank must be of sufficient size to be able to handle power requirements during periods when no new power is being generated. Systems are generally designed to only handle short periods (2-4 days) of times when no power is being generated. When these periods are exceeded, or when the system is not generating enough power in excess of that power that is being used, then the battery levels will drop to a level in which they must be recharged by another method.  In this condition, a generator is generally used to charge the batteries until such time as the solar or wind turbines can generate enough power to maintain the battery to the proper level.  A generator is an important component to any solar, wind or hybrid system as it will ensure that battery bank can be maintained to the proper level in the event of a failure of one of the solar or wind components or during periods of outages from either system.

So as you can see, regardless of which alternative system configuration you choose, there will still be periods when that system cannot generate power and you will need to have another means of providing power to the battery bank.  As we run these generators, whether on diesel, gasoline, natural gas or propane, there is an associated cost of fuel.  These costs can quickly add up if there is a requirement to run a generator for any extended period.  What if we could power these generators with fuel we created, thus eliminating these additional fuel costs?   That might very well be the missing link to our complete and independent power system.

 Wood Gas - the missing link

Wood Gas Generator

The process of producing energy using the gasification method has been in use for more than 180 years. In the early time coal and peat were used to power these plants. Initially developed to produce town gas for lighting and cooking in the 1800s, this was replaced by electricity and natural gas, it was also used in blast furnaces but the bigger role was played in the production of synthetic chemicals where it has been in use since the 1920s.

During both world wars, especially the World War II, the need for fuel produced by gasification reemerged due to the shortage of petroleum. Wood gas generators, called Gasogene or Gazogène, were used to power motor vehicles in Europe. By 1945 there were trucks, buses and agricultural machines that were powered by gasification. It is estimated that there were close to 9,000,000 vehicles running on producer gas all over the world.

Wood gasification also regained popularity in the 1970's during the oil embargo which lead to severe gasoline shortages in the US. It seems that gasification is something that gains popularity during times of an energy crisis, only to be forgotten when the crisis passes. It then has to be rediscovered and relearned when the next energy crisis arises. Today, gasification is commonly used in commercial applications, and is gaining popularity as a viable system for home power generation and emergency backup power systems.

Wood gasification uses a process called pyrolysis to break down organic matter into its basic elements, carbon and gases. This process is done in a high temperature, oxygen limited environment to breakdown the wood into its basic elements. The gas is then extracted, cooled and filtered and may be used as a fuel for direct heating applications or as a fuel to power a standard combustion engine. The gas produced by wood gasification consists of Hydrogen, Methane and Carbon dioxide, also referred to as 'Syngas' (Synthetic gas). It has similar properties to natural gas but is not considered natural gas. The syngas has a different air-to-fuel ratio that must be taken into consideration when used as fuel for a standard combustion engine.

Syngas also has a lower power rating than natural gas (50%-60%), which must also be taken into consideration when selecting an engine or generator size in a power producing application. For example, a 10KW propane generator would actually produce about 6KW of power when run on wood gas.

Using proven and efficient designs, today's wood gas generators can produce clean, abundant, and free fuel for many application including heat generation, home power systems, and emergency power systems when traditional fuels are not available or too costly.

Adding a wood gas generator to your off grid power system will provide that last component to ensure you are generating your own independent and free power, day or night, anytime it is needed.  In fact with today’s wood gas generators, it is possible to configure a complete system using only a wood gas generator and standard generator to charge the battery bank.  Depending upon the size of the system, running the wood gas generator every other day might be sufficient to provide all of the power needed, without the need for solar, wind or other alternative energy sources.

If you haven't yet considered wood gas in your alternative energy system, or if you would like to learn more about wood gas and its many uses, we would be glad to help you add this missing link to your energy system. 

 

Steven Honkus

OffGrid48°

http://offgrid48.com