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Renewables – it’s a kind of hobby/study

Green forms of energy aka renewables.

As part of my studies in WIT – Waterford I had to write up a list of renewable sources of energy. 3 might surprise you – by their inclusion.

  • Conserve  –  the best renewable. American scientists in the 90’s figured that every dollar spent on insulation was worth seven dollars of renewables.
  • Best build is one that is passive-solar – no need for external heat-source.  Passive Solar uses the sun’s rays to provide heat that is absorbed by the fabric of the building and slowly released when sun is not available.
  • Reuse – control airflow and heat-exchange – warm air exiting a building heats the fresh air coming in.
  • Use green-building materials-the greener the material the less ‘renewables’  need be used.
  • Use natural products in build and heating
  • Use natural products if heat is needed – wood, grass, renewable that doesn’t require the breakup of the earth (straw, beet, etc) anti-sequestering methods.
  • Use LED lighting preferably powered by solar-powered batteries if needs must then CFL will provide a cheaper alternative abet one that contains mercury and needs special end-of-life handling..
  • Energy can be created by using gym-machines or by expelled hot-air from buildings and machinery. (heat-exchangers and smale generators/dynamos).
  • Power can be generated from how-head medium volume water these days. Ie We no longer need to rely on high-head-high-volume water-wheels as the technology and systems improve. Old waterwheels of the Victorian-time worked at 20% capacity – these days this is reversed to 80% with Peltron wheels, Navitron systems and modern Francis-wheels.
  • Passive-solar simply means we orientate our homes towards the rising (or setting) sun to heat the home – or indeed away from same to keep it cool.
  • Glass conservatories to heat up and then direct heat into the home.
  • Old fashioned thatch – new-fashioned flame-resistant thatch.
  • Storing multiple 3Ton vats of water that is solar heated will provide warm water for days on end from the basement. The water helps keep the temperature stable and provides emergency water at times of need.
  • Rainwater-harvesting – toilets, animal drink, briquette-making.
  • Greywater-harvesting – save yourbath/shower water to wash the car/hen-coop, water the garden, veggie or simply use to hose the bikes after a day out.
  • Grow Your Own – from herbs to polly-tunnel we can all do a bit. Old water-guttering fixed to a wall or fence provides for a vertical garden in the smallest of spaces and then hens ….
  • Poultry – waste-disposal agents and eggs-on-legs. Scarifier of lawns and pest-control. Waste from hens feed the garden and hencoop waste goes into the compositor-bins in the garden to provide Nitrogen and paper/wood-pulp.


  • Mass-boilers – wood, pellets, shavings etc Lignum-products have been used since Prometheus brought fire from Zeus. Prometheus cared more for man than for the wrath of the increasingly powerful and autocratic king of the gods, so he stole fire from Zeus’ lightning, concealed it in a hollow stalk of fennel, and brought it to man. Prometheus also stole skills from Hephaestus and Athena to give to man.
  • (As an aside, Prometheus and Hermes, both considered trickster gods, both have a claim to the gift of fire. Hermes is credited with discovering how to produce it.)
  • Open-fires waste 85% of the heat up the chimney and replaces the volume of (warmed-air) twice every hour. A good well sealed stove will provide up to 80% of the energy from wood and if the air intake comes directly from an external source there is no wastage of warmed-air.
  • Mass boilers come in the range of; Multi-fuel (read; coal-turf & wood) stoves as are traditionally used in Agga, Sorn and Waterford Stanley style kitchen stoves, wood stoves, wood stoves with back-boilers, wood stoves with wrap-arond-boilers, and nowadays wood-pellet (mostly domestic) and wood chip (mostly commercial) stoves that all use thermal conduction, radiation and convection to spread heat – mostly though by heating water and passing that through radiators at 65C or ground-floor heating at 32C.
  • Brown heating can also be in the form of waste oil-heating either as a raw product (Glenribbeen) or refined to a bio-diesel (Lismore Rail Station). Used vegetable oil was seen until fairly recently as a nuisance-waste-product and only fit for (after much filtering) oiling machinery etc. Now it’s much in damand and can command a premium especially if its free from Animal Fat Acids (AFA;’s) which slow down the process of ‘washing the biodiesel’ as well as using up more.
  • Re-use of plastics to re-constitute kerosene. As proven by the multi-award-winning team from Lismore, plastic can be heated under pressure – with a catalist and will produse a useful gas and kerosene (with a little more work can also produce a motor-ready deisel.
  • Peat can be seen as a less favourable brownenergy though it must be remembered that ripping up bogs either by hand or worst by machine releases vast quantities of carbon into the athmosphere and will take 5000yrs to replenish – even if we were to give the earth the chance to do so.
  • Coal – aside from the harmful chemicals and heavy metals it releases (in mining, storage AND especially in burning) will take 1,000,000 minimum to replenish.
  • Oil- aside from the physical dangers, harmful chemicals and heavy metals it releases (in mining, storage AND especially in burning) will take 40,000,000 minimum to replenish. At least and we are using it total capacity usage in Max 400 years. This equates to one-year’s comsumption to 100,000 ‘growth’ of oil. Let us not forget however that the last 3 here are all products of earth and sun and though the embodied energy (ee) is huge – so too is the (possible) power that these natural products provide. If we are careful with it’s use.


  • White energy is that where we use grass (miscantus, willow etc) plants that grow without ripping up the earth and releasing the carbon sunk there) using solar and water (natural products) to create.
  • Wind Power. As the earth turns, various parts warm or cool and wind is the result of warmth moving to cooler areas. Wind moves in fairly well understood paterns but is hindered by earth-bund structures – mountains, forests, structures, individual trees, bushes and even area of grasses (wheat, corn). It makes it unstable as a resource.
  • Water-Power. From Micro to mid-hydro. Streams and rivers can be tapped to provide power locally. Many communities have nearby streams that can be tapped to provide up to 11kW even from a small 1m wide stream at 1:12. (see Glenribbeen)
  • Wave-Power. A fairly new idea – developing ‘ground’ in areas of high wave generation and action – ie W. Ireland and more particularly Scotland/Shetland.
  • Tidal Power- For millennia our ancestors used tidal-power to grind corn, seashells, turn wood and even saw wood. Now it’s recognised the rivers-estuaries like the Blackwater run at 18Kts twice a day (and 5kts in reverse twice a day). Huge potential – if wildlife can be protected.
  • Tidal Power- For millenia our ancestors used tidal-power to grind corn, seashells, turn wood and even saw wood.
  • Wind to water generation (The Spirit of Ireland). Wind is used to pump sea-water to flood (glacial) valleys in rural West Ireland and then when and as it’s needed the water is returned via generators to the sea and so provides a steady power supply.

White Magic;

  • Photo Voltaic (PV) the process where light (energy) is transformed into electrical energy. This can be a simple system like a conservatory heating the dark interiour of a house (passive solar) to the newer techniques of spraying T-Shirts with powder (in a vacuumed safe) to render them able to charge phones/GPS/radios when away from ‘standard’ load faciity. (
  • PV usage is ideal for outdoor lighting and long-term (hall) lighting where fiber optic is considered too expensive. PV offers a great way to light emergency lighting/exits in case of fire/power failour. As PV prices fall and their use more ubiquitous they are seen – along with the better batteries nowadays – as the way forward for transport where filling stations will fill batteries from banks of PV and cars either exchange batteries or load up with high-speed loaders at the “power-stations”.
  • ( More on solar;
  • Fiber-optic (FO) can provide free day-light from a rooftop to an office building and the electric light only comes on when the system senses a dull light from above. It’s reckoned that 60% of office energy in US is used on daytime office lighting.


  • Lighting homes and offices is one of the biggest factors in energy consumption presents a unique opportunity for technological advancement when it comes to efficiency.
  • PV for other power than lighting, PV was not seen yet as commercially viable for air-conditioning AC so long as petrol/gas remains below $1 a US gallon. Since that barrier has long been breached – in spite of President Reagan’s promise – PV is now used in Saudie Arabia by an Irish company to run AC, parking meters, de-salination units and much more.
  • Many other forms are being considered including using ‘geo-thermal-cooling’ to vent heat away from the back of PV panels in hot climates and using the subsequent current of air to turn a turbine to create yet more power.
  • Mirrors can be focused on a tower containing salt and this can be super-heated to drive turbines. The beauty of using salt is that it has a very high temperature stability and stays hot enough to work for up to three days enen if there is no sun.
  • Cars are being retro-fitted (at about $8000,- ) with energy conserving breaking-systems and batteries, to have them run in the same manner as the Prious. This innovation might put such ‘concept cars’ at the disposal of anyone who cares enough about the envirnoment.

Bicycles that create electrical power as one rides along. A little different from the simple dynamos on bike-wheels that I grew up with these babes generate enogh power to be useful without extending the effore of the cyclist. ( )

Geothermal (Gt) Uses water that is passed through pipes – either laterally in pipes one meter under the ground (meadow/garden) or pipes that are drilled vertically into the ground again to collect the residual heat from the earth and this is passed through an electric heat -exchanger. This in turnd heats the water which flows through pipes laid in the floors of the house. Note; underfloor insulation must be extensive and well sealed.

Heat is being taken from sewers and this in turn put heat exchangers to provide low-heat (30C) for underfloor heating for large (civic mostly) buildings where they are in almost constant use.

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