Renewable Energy Source.info

Smart Grid

Thu, 25 Aug 2011 20:14:07 +0000

Smart Grid attempts to predict and intelligently respond to the behaviour and actions of all electric power users connected by adding monitoring, analysis, control, and communication capabilities to the national electrical delivery system. It aims to maximize the throughput of the system while reducing the energy consumption. The Smart Grid will allow utilities to move electricity around the system as efficiency and economically as possible. It will also allow the homeowner and business to useelectricity as economically as possible.

With smart grid, it is possible to employ tactics for improved efficiency:

smart meters,
dynamic pricing,
smart thermostats and smart appliances,
automated control of equipment,
real-time and next day energy information feedback to electricity users,
usage by appliance data, and
scheduling and control of loads such as electric vehicle chargers, home area networks (HANs), and others.

Ground Source Heat Pump

Wed, 08 Jun 2011 20:44:31 +0000

A ground source heat pump (GSHP) or geothermal heat pump is a central heating and/or cooling system that moves heat to or from the ground. It uses the earth as a heat source for heating in the winter or a heat sink for cooling in the summer. Unlike an air-source heat pump, which transfers heat to or from the outside air, a ground source heat pump exchanges heat with the ground. This is much more energy-efficient because underground temperatures are more stable than air temperatures through the year.

Ground source heat pumps must have a heat exchanger in contact with the ground or groundwater to extract or dissipate heat. This component accounts for a third to a half of the total system cost. Several major design options are available for these, which are classified by fluid and layout. Direct exchange systems circulate refrigerant underground, closed loop systems use a mixture of anti-freeze and water, and open loop systems use natural groundwater.

Radiant Cooling

Tue, 07 Jun 2011 19:50:23 +0000

A cooling system that relies on temperature-controlled surface (ceiling, wall or floor) to cool indoor temperatures by removing sensible heat through thermal radiation. Heat will flow from objects, occupants, equipment and lights in a space to a cooled surface as long as their temperatures are warmer than that of the cooled surface and they are within the line of sight of the cooled surface. The process of radiant exchange has a negligible effect on air temperature, but through the process of convection, the air temperature will be lowered when air comes in contact with the cooled surface.

The majority of radiant cooling systems are hydronic, cooling using circulating water running in pipes in thermal contact with the surface. Due to the high heat capacity and density of water, thermal energy can be transported in water in pipes by low power pumps, saving approximately 70 to 80% of fan power normally used in conventianal air-conditioners.

Typically the circulating water in hydronic radiant cooling (HRC) only needs to be 2-4°C below the desired indoor air temperature. Since the coolant can be maintained at a high temperature level, the use of heat pumps with high coefficient-of-performance values, cooling towers, night cooling, or some combination of these can reduce electric power requirements further.

LED Lighting

Sat, 25 Dec 2010 20:09:34 +0000

LEDs or Light Emitting Diodes as a light source offer benefits in terms of maintenance and safety. The typical working lifetime of a device, including the bulb, is ten years, which is much longer than the lifetimes of most other light sources. Further, LEDs fail by dimming over time, rather than the abrupt burn-out of incandescent bulbs. LEDs give off less heat than incandescent light bulbs and are less fragile than fluorescent lamps. LEDs are built inside solid cases that protect them, making them hard to break and extremely durable. Since an individual device is smaller than a centimetre in length, LED-based light sources used for illumination and outdoor signals are built using clusters of tens of devices.

Lunar Solar Power

Sat, 26 Jun 2010 13:33:00 +0000

A Brief Description:

Lunar Solar Power (LSP) is one of the two general concepts that have been proposed for delivering solar power to Earth from space. One proposal calls for a huge satellite in geosynchronous orbit around Earth that gathers solar power in space. LSP is the second concept which envisions solar power being collected on the moon. In both ideas, many different beams of microwaves would deliver power to receivers at sites located worldwide. Each receiver, called a rectenna, would supply commercial power to a given region.

Prosperity for everyone on Earth by 2050 will require a sustainable source of electricity equivalent to 3 to 5 times the commercial power currently produced. Solar power generation is viewed as one of the solutions to meet the requirement. Although energy coming directly to Earth from the sun is renewable, weather makes the supply variable and their energy output is too expensive to collect, store, and dependably distribute. Unlike sunlight, microwaves pass through rain, clouds, dust, and smoke. In both scenarios, power can be supplied to the rectenna at night Several thousand individual rectennas strategically located around the globe, with a total area of 100,000 km2, could continuously provide the 20 TW of electric power, or 2 kW per person, required for a prosperous world of 10 billion people in 2050.

The concept of LSP came about to address the estimated huge costs to launch the sattelite based power generation and its environmental impacts. The Moon has no atmosphere, rain, or clouds to block sunlight as does the Earth. Doing the construction on the Moon is far less expensive than sending raw or processed materials to deep space for an orbital solar power generation system. There are fewer manufacturing operations. You do not have to build the platform. All the necessary technologies are believed to be in place to implement LSP.