FAQ

Why was OTGL database made ? + how to use this forum ?

The OTGL database was made to address a number of issues that were blocking the transition towards a system of ecologic, and self-sufficient energy production. These were that:
* most people don't have much practical knowledge on microgeneration and as such don't know what type of systems they can use to generate power, nor do they know how much energy they need to produce to become (at least partially) self-sufficient. They also don't know how best to set up their system so that they can reap the full rewards (financial benefit through systems like net metering, differences in price of different biofuels, energy storage capabilities, ...) of setting up such a self-sufficient (or at least partially self-sufficient) system
* Luckily, there is now a large amount of manufacturers of energy generators. In the past small energy generators were often not commercially produced meaning you needed to make every single part of your energy system by hand. Since most people weren't able to do this, they never created a self-sufficient energy system. However, despite that there are now commercial energy generators available, there is still no global archive listing these manufacturers, nor is there any listing of these manufacturers per location (which is rather essential as people generally want buy locally, to reduce shipping costs, and also for reasons of after-sales service/repair).

The OTGL database was initially started as an (osCommerce) webstore, but was later-on changed to an open-source database, so that the information contained herein was not only free, but texts, ... could also be copied freely (no copyright, all in the public domain).

Due to the new direction we took with the OTGL database, we also decided in focusing more on DIY (do-it-yourself) versions of the equipment. This, as we allready had the listing of the commercial manufacturers set up, and we wanted to do something more/engage with the community. Also, by sharing more details of these, we could improve the people's technical knowledge of the devices. A secondary result of this increasing the technical knowledge of the community is that it also becomes easier for people to repair their own equipment in case something fails. Also, with the (metal-based) commercial (and home) 3D printing coming up, it becomes ever easier to keep repairing even older equipment (as -no longer commercially sold- parts can now still be printed).

An e-mailadress was also added to provide the community a means of giving feedback to us. People can use it to ask questions on the OTGL/post any requests for corrections of texts and/or the adding of new info in the OTGL, ... The OTGL FAQ section is kept to provide general information and any information herein is subject to change by the admin, based on the questions/requests posted via the e-mailadress.

Products that can be made DIY

In the product descriptions of many of the OTGL products, you can find info on how to make some things at a DIY (do it yourself) method. This can obviously reduce the cost, and is also an option for people that live in an area where ordering the product they want can be costly (shipping costs) or even impossible (product not being shipped there). It also allows to make your equipment completely the way you want it (customization, and possibly making it a bit more efficient).

This paragraph doesis not intented to list all products of the OTGL that can be made DIY. Instead, it's intented on giving some additional advice/info on specific DIY-capable products.

* The heat recovery ventilation system: schematics on how to make this can be found at
http://www.appropedia.org/File:Heat_rec ... ematic.png
http://www.appropedia.org/File:Counter_ ... hanger.png
The fans used can be regular computer fans

* The optimized DIY air-source heat pump is basically the Strawbridge air/ground-source heat pump system but with several modifications. You could still order most parts from REUK.co.uk, and simply make some parts yourself. The way on how the optimized system works is as follows:
The heat pump system consists of a pipe from the top of the shelter down to a network of perforated pipes inside a plywood box filled with glass objects filled with water, or alternatively stones, ... The plywood box is placed under the soil. A fan is present inside the pipe to move hot air accumulating at the top of the shelter down to the glass/water (which works as a heat sink). The fan is run during the day (operated by a PCB or time switch, fed by a battery or from the mains electricity grid,) and deactivated at night. At night (when the shelter cools down and when sub-zero temperatures may be reached), the heat stored in the heat sink travels upwards out of box via a valve (this valve is then opened by the PCB as well).

* The solar thermal collector: The custom version was based on the Zaragoza solar water heater , yet has been given several improvements:
* the tank is placed lower -at the same height and size of the collector-. This allows the pump to work less hard, increasing efficiency.
* Another major design flaw of the Zaragoza was that there is no metal between the pipes guiding additional heat to the pipes. This metal can be either a bend flat plate or fins; see
builditsolar.com/Experimental/PEXCollector/PEXCollector.htm and
builditsolar.com/Experimental/CopperAlumCollector/CopperAlumCol.htm
* The metal used for the entire interior should be aluminum. Using a single metal (rather than several types of metal for different parts) eliminates heat loss. Using aluminum instead of copper has the benefit that the device will be cheaper, nearly equally efficient ( thermal conductivity of aluminum is almost the same as of copper and ensures that no copper is used for this device (copper is best used only for applications where it is really indispensable)
* Other improvements may be painting the box of the device black, correct tilt of the collector to the sun , depending on location (latitude) and season of the year, facing true south or north (depending on hemisphere), insulation on outgoing pipes and making these pipes to the boiler as short as possible

What is the best continuous power plant ?

If you read the other posts at this forum, you noticed that continuous power plants (like biofuel-based energy generators -a.k.a. fuel engines- and water-based electricity generators -a.k.a. turbines or water engines-) are preferred as they allow the dismissal of an energy storage system. So, logical additional questions are:"What type of the above mentioned energy generators should I take ?", "What water-based energy generator should I take ?" and "What fuel engine should I take ?"

The response to the first question is: use a water-based energy generator if you live near a river. If you don't live near a river, you off course need to resort to using a (gas, liquid or solid) fuel engine. Water-based energy generators are preferred over fuel engines as you obviously don't need to attain fuel for them to run/produce the electricity you want. What water-based energy generator you should take is simple: use a low-head turbine (this is also the only type mentioned in the OTGL). We only mentioned this type as we can't expect people living near a stream to also have much elevation difference along the river. Also, high-head turbines often require more work on changing the stream bed of the river. If you do have a large elevation difference on your river, you might want to opt for a high-head turbine. Do note however that these are not more efficient, they're just a different type of turbine.

Then the question to what fuel engine you should take.
Undoubtably, you've been comparing engines like the internal combustion engine (gasoline and Diesel), Stirling engine, ... and found that the efficiencies vary ; 30% for gasoline engines, 35% for Diesel engines, and 40% for Stirling engines. You probably also noticed that at the OTGL database, gasoline engines are used for the gas engines, and Diesel engines are used for the liquid fuel engines. So why do we use them both if the efficiencies vary ? The answer is simple: Diesel engines rely on compression ignition whereas gasoline engines rely on spark-ignition. This fact makes Diesel engines better suited for running on a liquid biofuel like straight vegetable oil (as the compression ignition is sufficient to ignite this fuel) whereas a spark-ignition is a necessity for igniting gaseous fuels like biogas, pure methane, and wood gas. It should be noted that for the gaseous fuels there are some workarounds though to still make it possible to use a Diesel engine with these as well (for example by running the engine in flexible-fuel mode (hence mixing the gas with some liquid biofuel) or by simply adding a spark-plug to the Diesel engine -see US carburetion for example- ). These workarounds are always patchwork solutions though, and also require extensive knowledge to execute them correctly. As such, you better buy an engine that is immediately up to task it is designed for (such as the ones presented at the OTGL database). Also note that the Diesel engines we selected are of the Lister CS/Petter type. These engines are foreseen with indirect injection, which is by far better (if not essential) for running on a liquid biofuel like straight vegetable oil. The gasoline engines too use an indirect injection as it is essential for running on a gaseous biofuel (like wood gas). Also note that whenever possible, we opted for liquid-cooled engines rather than air-cooled engines as the former type allows to reuse the waste heat for other applications (for example for heating water, rooms, ...) Besides being an indirect injection engine, the gaseous fuel engines that run on wood gas are also outfitted with a an additional T-junction and butterfly valve . By contrast, fuel engines that run on biogas or methane don't necessarily need to be indirect injection engines, especially if you buy an engine that was purpose-built to run on this fuel. It should be noted that these gaseous fuel engines that run on wood gas are listed at the OTGL database as "solid-based electricity generators". This as we looked at the engines from the fuel perspective, and wood gas is off course generated from wood (stick wood, wood chips, nut shells, husks, ...). The solid-based electricity generators do not just include the gasoline (or in some cases Stirling) engine but also the wood gasifier and all other necessary components. Note that we also listed some wood gasifiers on themselves (without engines and extra components). These products begin with "Gasifier (wood gas, from wood,..." They are intented to be combined with a suitable gasoline engine to build your own system. It should only be done though if you still have a suitable engine laying around and if you feel up for the task.

We looked at the engines from the fuel perpective as this will be the most important aspect you should focus on when selecting an engine; the efficiency of the engine is (far) less important. Before you even begin to wonder about the efficiencies, you should first ask yourself what biofuel you can get your hands on (what fuel you can produce on-site, or at least buy cheaply at your location). This may be wood (from your trees, nuts/pits from your crops, ...), straight vegetable oil (from your crops), biogas (from your biodigester handling your feces disposal; assuming you have one -only useful when combined with flush toilet, not composting toilet), ...

Combine the correct engine with the correct class of gasifier (woodgas gasifier, biogas gasifier -a.k.a anaerobic digester-). A size XS gasifier is too small to be combined with any engine to be cost-effective. A size S biogas gasifier would be suitable to be combined with a size S biofuel (biogas)-based electricity generator. A size M biogas gasifier would for be suitable to be combined with a size M biofuel (biogas)-based electricity generator. A size L biogas gasifier isn't listed as gasifiers that big are not useful by many people or even enterprises. Finally, similarly to the biogas gasifiers, the woodgas gasifiers have a same gas output classification as the energy generators (sufficient gas production for 100 kW for the L-class, 15 kW for the M-class and 5 kW for the S-class). Hence connect an gasoline engine that is able to receive a same amount of gas.

Also note the different classes of power production with energy generators. The energy production per class (small, medium, large) varies per type of equipment.
Biofuel-based electricity generators produce 5 kW in the small version, 15 kW in medium version and 100 kW in the large version.
Water-based electricity generators produce 1 kW in the small version, 3 kW in medium version and 20 kW in the large version.
Wind-based electricity generators produce 1 kW in the small version, 3 kW in medium version and 20 kW in the large version.
For a family house, a 1kW to 5 kW energy generator is sufficient (depends on how many appliances you have running, whether you have an energy storage system, want to produce power to resupply to the mains electricity grid via net metering, ....) A 15 to 100 kW energy generator can supply sufficient power to the mains electricity grid to help power a small neighborhood.

Why we didn't list any "solar panels"

A question often heard at this site is why there aren't any "solar panels".
Well, actually, we did list solar panels, and even the most efficient/ecologic kind of solar panels namely the thermodynamic solar panel (also called "flat-plate solar thermal collectors). We didn't list any photovoltaic (PV) solar panels, because we don't believe that this technology is suitable for the main energy production of a family house, neighborhoods, ... They can be valuable however for the recharging of very small (battery-based) systems such as for example the air-source heat pump that we list at the OTGL database.

The reasons why we don't think that this aerospace technology isn't suitable for the main energy production of a family house, neighborhoods, ... are:
* PV solar panels are a very high-tech technology that can't be repaired by individuals, nor made at home
* PV panels are rather inefficient ( only 15% efficient )
* PV solar panels are made at a rather environmentally polluting method
* PV solar panels only have a limited life span (20 years or so)

Remarks on avoiding IC engine conversion

You probably read about the types of internal combustion engines (gasoline, Diesel) and what biofuels they can be made to run on at the post entitled "What is the best continuous power plant ?". In general, the post noted that Diesel engines can be run on lipid-based fuels such as straight vegetable oil, whereas gasoline engines could be run on wood gas and biogas.

The post however also informed you that the Diesel engines needed to have an indirect injection system to be able to run on lipid-based fuels such as straight vegetable oil (SVO). Another option explained at the "Diesel engine conversion kit" product descriptions at the OTGL database was to add additional equipment for preheating the SVO in your direct injection Diesel engine, hereby making the fuel "runnier" and so allowing it to pass through the direct fuel inlet unhindered. Since most recent Diesel engines are fitted with direct injection systems these days, you thus might not be able to use SVO unless you do this conversion. However, if you feel not up to this task but still want to run your Diesel engine on a biofuel, then what options do you have ?

The answer to this is biodiesel. Biodiesel is basically straight vegetable oil (or even waste vegetable oil) that has been cleaned up by a chemical process involving small amounts of potassium hydroxide or sodium hydroxide. A full description can be found here , or you can view the same article/images at the AT CoLib. If you want to produce biodiesel, you need to learn about this process and get the required chemicals and biodiesel reactor (or make one yourself). In some cases, it may also be possible to simply purchase biodiesel in nearby fuel stations.

Then for the gasoline engines: with these too, direct injection engines are the norm today, so you might have a direct injection engine and are thus unable to use wood gas. So what options do you still have, without doing a conversion to an indirect injection gasoline engine ?

One answer is biobutanol. This fuel can be used as is in direct injection gasoline engines. However, biobutanol isn't sold much/widely available, and producing it at home is also tricky/not frequently practiced. Another option is to do a very minor conversion and use an alcohol as a fuel (like ethanol which you can easily make at home using a still). It should be noted that methanol too can be made at home, but it is very toxic (can cause blindness), so preferably use ethanol instead.

Other options for unconverted gasoline engines are biogas, methane, oxyhydrogen and syngas. As mentioned at "What is the best continuous power plant ?", biogas does not require the gasoline engine to be fitted with an indirect injection system. That doesn't necessarily mean though it will also always immediately work with your direct injection gasoline engine, so slight modifications may still be needed. The same goes for the other gases. Biogas and methane can be produced at home from your anaerobic digester. Oxyhydrogen can be made from water (using an electrolyzer, for example the Bob Boyce Electrolyzer), and syngas can also be made
from water and CO2 .

Determining your energy storage capacity

In determining your energy storage, you will have probably face the question on whether you should set up your system with an energy storage system, and what capacity this would need to have or whether you should go for a system that doesn't have any energy storage system at all.

This question isn't very easy to answer, and depends on what appliances, ... you wish to have/run (if you read the all product descriptions carefully -see for example the Electricity-powered refrigeration kit, Biofuel-powered refrigeration kit, Oil lantern, Wind-up lantern and Mechanical pocket watch product descriptions-, you will see this has been mentioned at the OTGL as well). In general, first try to eliminate as much as possible appliances that need continuous power. In certain cases, you may wish to convert any appliances you have and that do need continuous power so that they are able to be temporarily disconnected from the mains electricity grid (or your renewable energy power plant -with or without energy storage system-) without much trouble. For example,

* if you don't want to get rid of your regular kitchen refrigerator, you can:
** place it in a colder room/area
** add thermal mass (see here ) to your refrigerator

* if you don't want to get rid of your digital clock on your sleeping room, you can possibly add electrochemical cells (AA) to them so they can switch to these during mains power outtages, ...

* For some tasks, you may also switch to using mechanical devices/devices that have their own energy source. For example, to keep track of the time, you can also use a mechanical (spring-powered) pocket watch.

Also, try to come up with different ways to handle things than by using (electric or mechanical) devices. For example, try to preserve food at many other ways as well, besides solely relying on refrigeration. See Food preservation . For keeping track of the time, you might also be able to use a sun dial, ... For transport, you don't always need an electric vehicle but you might do with a velomobile (if need be, a hybrid one with only a small biofuel a small electric engine), roller skates, ...

If you do find that despite all these tricks you still have appliances that require a continuous power supply to function properly (can't be converted to cope with temporary power interruptions, see above), then you can either
* accept that for the functioning of these, you are still dependant on the mains electricity system (if you have a connection to the mains electricity system (aka grid-connected/grid-tied system) and the power supply of mains electricity grid is reliable where you live) than this won't be a problem.
* OR add a continuous renewable energy source to your system (with "continuous energy generator" we mean an electricity generator that can generate power continuously -for example a biofuel or water-based powered energy generator instead of say a wind turbine-). Note that with some biofuel-based generators, you may need to still feed the generator with new fuel once and a while, but still the generator can be made to run continuously. In instances, where you run all your appliances directly from the renewable energy generator you should also use the trick of timing when you do energy-intensive tasks (i.e. use of washing machines, ...).
* OR add an energy storage system (battery-based, pumped hydro or one that uses compressed air tanks to store the power in). Your energy storage system can then be recharged either
** by the mains electricity grid OR
** by your renewable energy generator (if you have one).
The first option (recharge by mains electricity grid) still creates a dependance on the mains electricity grid, but less so than when you don't have an energy storage system. This, as your energy storage system will work as a buffer so even if the mains electricity grid is down often, you can recharge in the small length of time in which it is operating. An other advantage is that you can recharge during off-peak hours (the period of the day in which the least power is consumed from the mains electricity grid). This electricity is often much cheaper, meaning you can take much financial advantage of simply having an energy storage system, even if you don't combine it with a renewable energy generator.
The second option (recharge by your renewable energy generator) creates no dependance on the mains electricity grid and may even be cheaper still than recharging your energy storage system from the mains electricity grid. The financial benefit will be smaller or greater however depending on which fuel you use and whether you are able to produce your own fuel or not.

This sums up all the different options you have on how you can set up your energy system. Clearly, you will need to think about what option will best suit you an implement this. However, do try to reduce the capacity of your energy storage system as far as possible, in the event that you do decide you really need one. Also reflect on the benefit community/neighborhood benefit that the including of a (continuous or even non-continuous) renewable energy power plant provides (in terms of making the mains electricity supply for your neighborhood more reliable and helping the global green shift/move towards the use of renewable energy production). It should be noted here, that the larger the renewable power plant you install, the larger the benefit will be, and the more money you may earn (through net metering). Also note that, as briefly mentioned in this paragraph, the use of even a non-continuous energy generator will help in all this. The only reason why we prefer continuous energy power plants is for allowing you to generate power continuously, or exactly at the period in the day when you require it, without needing to resort to using an energy storage system (as this option is less ecological/economical than using the energy of biofuels). However, for net metering purposes/feeding the mains electricity grid, this is of little consequence (well, generating power during high power consumption -peak hour electricity- does allow you to gain some more revenue per watt produced but that aside).

Best way to heat rooms

Unless you read the product descriptions of "Biomass-based water heater", "Portable electric radiator" and "Heat recovery ventilation system" very carefully, you might of missed that the best (most economical/ecologic) way to heat your house rooms will vary per family/house. This as there may allready be heating sources present in your house (and you best make these a bit more ecological, no need to buy new/other heat sources), and it might also depend on the level of convenience you want (i.e. biomass (wood)-based heaters require a lot of attention/work compared to say an electric heater).

If you allready own a (fossil fuel-based) central heating system with radiators for example, you best simply convert this to either use
* a liquid biofuel (say biobutanol, bioethanol, straight vegetable oil, biodiesel, ...). Prices of these fuels vary greatly, some may simply be unaffordable to use at present if you don't produce it yourself. Others, such as straight vegetable oil are very affordable to use, even more so than fossil fuels. What you can use as fuel however depends on what burner you have. Since burners aren't engines however, there is a good chance that you should be able to use the cheaper fuels (as straight vegetable oil). Do make your homework (research) however before you put in a different fuel. The burner might need some tweaking before it is able to run on the fuel you want to use.
* or wood. This can be easily done by just discarding the entire fossil fuel-based heater and swapping it with a wood burner (see Biomass-based water heater product description). The downside of this however is that you thus can't reuse your old fuel-powered heater. Then again, if it was broken anyway, this option might be better, ...

If you didn't/do not have a central heating system with radiators, but nonetheless have some heat sources, you might have problem with not being able to heat up all rooms in the house (and/or have heat sources that might be overkill for the room they are placed in). Top solve this, buy or make a heat recovery ventilation system. This spreads the heat over all the rooms in your house evenly. An alternative (or in addition to this) you can also buy an additional electric heater; preferably one that is movable so you can take it along to any house room.

Remarks on "main hot water system"

The mentioned "main hot water system" proposed by the Second Chance Network refers to the ODWHES (found here ) The ODWHES is build up either
* using a solar thermal collector hooked up to an electrical (tankless) heater OR a solar thermal collector hooked up to a biofuel-powered (small tank-based) heater. In both cases, the amount of energy that needs to be put in (by the electrical or biofuel-powered) heater is minimal as the solar thermal collector has allready preheated the water to a certain level (say 20 to 40° celsius). The ODWHES can be used to any hot water faucets (i.e. kitchen sink hot water faucet) as well as the shower of a small family residence, ...

The communal shower room design is useful for a larger institution (many people) and is a dedicated shower system. It uses an own solar (batch) heater and an own dedicated electric heater. The schematics can be found at the minimal collection of images at healingweb and the model can be downloaded from here .

It should be noted that one can off course compose his own hot water system, the systems proposed are just systems that are energy-efficient to use and should be usable by most people. Regardless, you can also decide to compose your own system. This is useful, for example if you have a house where there is allready an electric or biofuel-powered large boiler present. If that's the case, you can continue to use that boiler and for example just make it a bit more ecological/efficient by adding a (flat plate) solar thermal collector or by adding a biomass (wood)-based water heater. Besides paying attention to how you heat the water, also don't provide hot water to all your faucets. In many cases, this is simply not needed.

Remarks on the velomobile motor

The electric motors by Akkurad were chosen because they have experience with fitting electric motors to velomobiles. As such, they can give advice on what electric motor you best choose for your particular velomobile. The engines/drive trains they sell allow to be combined with the allready present bicycle gears, which is useful for setting up the vehicle for true hybrid propulsion (meaning that you will still be able to propel it on human power alone if the battery dies or if you want to conserve power).

Also, besides the electric motor, it is also possible to connect a 4-stroke engine to a velomobile, instead of using an electric motor. This has the advantage that no batteries need to be used (no recharging, ...). A 4-stroke engine can be run on ethanol or biobutanol. A disadvantage may be however that it may not be possible to combine it with the bicycle gears, meaning that in human-power only mode (motor switched off) it will be more difficult to propel the vehicle. Suitable (low-power; ie >2HP engines) may be attained via manufacturers that produce motorized kick scooters .

Remarks on the potable water filter

It should be noted that a little water should be made to pass through the actual potable water filter ( >5µ filter ). As such only connect those faucets that really require it to the piping behind the potable water filter, and connect the other faucets to the piping before this filter (after the coarse filters). Most water will only need to pass through the coarse filters as for most purposes (cleaning, use in low-flush toilet, ...) non-potable water suffices. By setting things up so that only the water that really needs to be potable passes trough the potable water filter, the life span of the potable water filter can be extended. Also note that it is also possible to combine the water organising module with staged reusing of the water .

Also, besides using filters, it is also possible to use a water cooker to make the water safe to drink. Simply boil the water for 6 to 7 minutes for this. Do note though that some solid contaminants won't be removed from the water this way. so if there are any such contaminants present, use a solar-powered, or electric still. Solar-powered stills can be easily made DIY.

Why we chose that manufacturer + use of the 1-piece garment

We think it is best to choose garments made from recycled material or use "organic" garments . The latter do to not use materials coming from fields were the use of pesticides is still allowed, and more importantly, also make sure that no chemicals (fabric softeners, bleaching agents, ...) are used in the production process. These chemicals may causing irritation of the skin and also cause major soil and waterpollution in the area of production. This is why Repair the World was preferred as the manufacturer.

A one-piece garment is useful for in both hot and cold countries and helps to conserve energy. It hence allows you to reduce the heating required in your house (cold environments), or reduce the cooling required (hot environments). The reason why one-piece garments are so good is because the air layer is uninterrupted, over the entire body; this is the reason why it is the traditional clothing worn in hot countries (see http://en.wikipedia.org/wiki/Djellaba ) as well as cold countries (see http://en.wikipedia.org/wiki/Sami_people )

A one-piece garment is also multifunctional, and can be worn for various occasions. It can for example be worn as a casual indoor garment (do pick one that has soft textile though, so don't use a coverall-style one-piece garment for this purpose). It can also be worn for hunting (pick one with natural colors for this, so either yellow, brown or green (to match the surrounding environment).

What's the deal with the prepper groups ?

You probably noticed the prepper meetup groups map at the AEP main page and wondered what these had to do with a site focused on greening the power generation and ecotourism.
The answer is simple: prepper groups are, despite being a bit offensive in their approach, often all ready busy on setting up local, self-sufficient systems (on energy, water, agriculture, waste management, ...). As such, they are the ideal contacts to get in touch with to exchange information, ideas, ... as well as to help real-life practical help on. By allowing interaction between green (pacifist) groups such as ours, and (the more offensive) prepper groups, we will thus be able to set up green, self-sufficient systems quicker.