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4.0 RENEWABLES
Governments and corporations have adopted the so-called "zero-based budgeting". In this concept, the budget is given a cut-off date, beyond which, everything is reviewed as if they are for new projects, altogether.
It is my personal belief that ALL, absolutely ALL, engineering assumptions for renewables should be subjected to the zero-base concept. For example, the wind assumptions used for the engineering design of wind turbines will vary from one location to another, even in the same country. I am, therefore, saying that an efficient wind turbine developed by CompanyXX for one location will not necessarily be beneficial for another location. A very efficient generic design for a windy area in Hawaii, or other parts of the world might simply become a tourist attraction of turbines that decorate the landscape, but run only a small percentage of the time.
4.1 Engineering and Equipment Design Assumptions
4.1.1 What are the prevalent conditions for the most part of the year? Consequent to this question is the decision to aim at the most optimal "area in the duration curve", to optimize the harvesting of renewable energy.
4.1.2 This leads to the rule that I am breaking up into two parts.
4.1.2.1 DO NOT DESIGN for SYCHRONOUS speed for "off-grid" or "decentralized energy systems". Provide "variable speed" generators that are able to span the range of speeds provided by "renewables". Off-the-shelf "automotive generators" are cost-effective solutions, because they operate from a low of 750 RPM and a high of 6000 RPM.
4.1.2.2 Where needed, and to the extent needed, use inverters to drive AC motors. Where a choice is possible, my recommendation is to use 3-phase motors that are driven from 3-phase inverters.
4.2 Implementation of Renewable Energy Programs and Projects
The term renewable resources does not always mean renewable in its strictest sense. I like to give it a very broad meaning as those energy sources that do not come from fossil fuels.
Historical engineering practice often prevents us from developing these resources because we often forget the fact that fuel oil is a commodity that can be bought and sold. As such it is prone to manipulation as many geopolitical economies and forces leverage this commodity for higher and higher profit. As a consequence, renewable resources are really not taken very seriously until the tight energy squeeze comes.
Traditional engineering concepts like frequency, synchronous speed, grid interconnection, and the like have enclosed engineers around the world in a closed box. Engineers who dared think in terms of direct current stored in batteries and used directly or passed through inverters to provide alternating current for AC motors did not get much attention, let alone "funding".
They are told to follow engineering practice as preached by global consultants hired by utilities and confirmed by engineering textbooks and handbooks. They are told that the project carried a very high unit investment (US$ per kilo-watt of installed capacity), and the payback time of the investment is either too long, or non-existent.
I am proposing design changes and new configurations in the succeeding paragraphs.
4.2.1 Micro-Hydros
4.2.1.1 Run-of-River
Hydro-Electric power plants are usually provided with an impounding dam to collect the water that will be sent to the hydraulic machine downstream to generate electricity.
Such dams are called "storage dams" when they are able to collect plenty of water, and "run-of-river", when they simply stabilize the water flow into the hydraulic turbine.
* Control Systems
Such machines are often rated as 60 Hz or 50 Hz, depending on the geographical region in the world.
The frequency thus severely restricts their shaft rotation to that which will generate the desired frequency, requiring sophisticated speed governors to control the frequency and automatic voltage controls to control the voltage and the power factor of the machine.
* Design Changes
In a new approach, there will be no need for a sophisticated speed governor, or a sophisticated voltage control system.
- The shaft will simply turn according to the water available, and generate whatever electricity is available from the power at the shaft.
- The alternating current generated here is rectified into pulsating DC.
- A less sophisticated "semiconductor-based switching" system provides high voltage charging current to large batteries.
- Power from these batteries is usable as they are, or it could be converted into alternating current for use in AC motors, as may be required.
4.2.2 Wind
The approach will be very similar to the one described for micro-hydros, above.
4.2.3 Tide
The approach will be very similar to the one described for micro-hydros, above.
4.2.4 Wave
The approach will be very similar to the one described for micro-hydros, above.
4.2.5 Ocean current at the Philippine Deep
The approach will be very similar to the one described for micro-hydros, above.
4.2.6 Solar Water Heaters for Ocean-Thermal and Air-Conditioning Applications
* Solar energy is collected using ordinary GI (galvanized iron) pipes.
* It is sent to a heat exchanger to send the energy to a client process
* Ocean-Thermal is one such process
* Absorption refrigeration systems for air-conditioning is another example of such a process
4.2.7 Ocean-Thermal
* This system assumes that it is environmentally sound to withdraw cold water from the Philippine Deep
* The energy from the solar water heater is made to evaporate a refrigerant medium, or a petroleum compound
* The vapor is used to drive a vapor turbine
* Like the steam turbine, the shaft of the vapor turbine is also coupled to a generator to generate electricity.
* The required energy gradient is provided by the cold water coming from the Philippine Deep, and it will cool the vapor in the turbine to condense it.
* After the water has condensed the vapor, its temperature would become close to ambient, and will now be sent to an oyster farm or fish-culture farm to deliver the abundant nutrients that it carries with it.
4.2.8 Binary Cycles for geothermal and solar applications
* These applications work in very much the same way as the Ocean-Thermal, with the exception that the cooling medium does not come from cold water from the Philippine Deep, but from a river, a deep-well, or a cooling tower.
* The fluids from the energy source, i. e., geothermal and solar are isolated by heat exchangers from the fluids that go through the vapor turbines.
* The heated medium will be converted into vapor to drive a vapor turbine.
* The vapor is condensed in an atmospheric condenser which derives its cooling from water from a river, a deep-well, or a cooling tower.
* In other words, replace the cooling medium here with water from deep in the ocean, and the system converts into an Ocean-Thermal installation.
* The finer points of differences would be the working pressures, temperatures and fluid media.
* The design will take cognizance of these.
4.2.9 Biomass
The technologies in vogue here are usually related to the combustion of biomass, such as,
* combustion of solid waste, rice hull, coconut husk, coconut shell, wood, etc.
* straight combustion of municipal waste (garbage)
* the incomplete combustion of garbage, coupled with a process to recover the resulting products and convert them into ethanol by a bacteria digestion process.
4.2.10 Bacteria Digestion
* Several different digestion bacteria have been collected by different entities.
* Some for the production of vinegar, others for the production of methane gas from human, animal, poultry, and vegetable waste.
* Some bacteria are able to digest hot toxic liquid waste at 60-degree Celsius from sugar centrals into methane gas.
* This gas is sent back to boilers or burned in other heating equipment.
* The effluent liquids and solids are sent to the fields to become fertilizer for rice crops and other plants.
4.2.11 Recovery of Deuterium at the Philippine Deep
* The Philippine Deep is said to have the largest supply of Deuterium in the world.
* This substance is used in the development of fusion reactors in New Jersey and other centers. Some extract Hydrogen from Deuterium and use the Hydrogen as fuel.
* Since the supply is within Philippine territory, the Philippines could potentially become the "supplier of choice" for Deuterium once the fusion reactors become commercialized.
* Deuterium may be sold in its raw form and packaged in such a way that it does not disintegrate into plain Hydrogen gas, while in transit.
* Another approach would be to set-up the facilities near the Philippine Deep and utilize Deuterium to produce Hydrogen and Oxygen gases to be exported for use in fuel cells around the world.
4.2.12 Deriving Ethanol from Municipal Waste
* A technology already exists that will burn municipal waste in a boiler, retrieve the gases of combustion and feed that into a digester to generate ethanol. The products will be electricity, ethanol, and exhaust gases that are more environment-friendly than those coming from traditional waste-to-energy technologies.
4.3 Distribution Criteria
* Distribution will depend upon the clustering of the energy sources and of the loads.