Socioecology Research Today » geothermal

Thermo-economic assessment of a micro CHP system fuelled by geothermal and solar energy

A. Cherson — Wed, 20 Mar 2013 02:17:54 +0000

A micro combined heat and power (CHP) plant operating through an Organic Rankine Cycle (ORC) using renewable energy is analysed. The reference system is designed to produce 50 kWe. The heat sources of the system are geothermal energy at low temperature (80–100 °C) and solar energy. The system uses a solar field composed only by evacuated solar collectors, and work is produced by a single turbine. Different working fluids (e.g. R134a, R236fa, R245fa) are considered in the analysis. The aim of this paper is to assess the cost of the proposed CHP plant and to determine the most convenient working fluid through a thermo-economic analysis. The system is sized in base of the weather data of a city in the centre of Italy in three different months (January, March, July), and the main characteristics of the system (i.e. heat exchanger surface, solar collector area) are presented. The results of the thermo-economic analysis show that R245fa allows the lowest price of electricity production and the lowest overall cost of the CHP plant.

http://dx.doi.org/10.1016/j.energy.2013.01.058

Municipal solid waste landfills as geothermal heat sources

A. Cherson — Sun, 27 Jan 2013 00:55:57 +0000

It is well established that ground-source heat pumps (GSHPs) require less external energy input than conventional heating and cooling systems for buildings because they exchange heat with the subsurface soil and rock, which has a steady temperature compared to that of the outside air. To address barriers to implementation for GSHPs, incorporation of heat exchangers into civil engineering infrastructure is being investigated to reduce installation costs. Of these infrastructures, municipal solid waste (MSW) landfills may be a potential source of heat for GSHPs due to their elevated temperatures associated with the long-term, exothermic decomposition of organic materials within the waste. To assess this potential, this paper provides a review of studies focused on characterization of the thermal resource of landfilled MSW. Further, the potential impacts of heat exchange on rates of methane generation, hydraulic performance of landfill liners, and clogging of leachate collection systems are evaluated. Based on landfill construction requirements and different approaches for GSHP installation used in practice, configurations for geothermal heat exchangers in landfills are proposed for different landfill operational and closure scenarios. An economic analysis of geothermal heat exchange in MSW landfills indicates that they are expected to provide an accessible and sustainable thermal energy resource.

http://dx.doi.org/10.1016/j.rser.2012.07.028

Pairing Integrated Gasification and Enhanced Geothermal Systems (EGS) in Semiarid Environments

A. Cherson — Mon, 31 Dec 2012 21:47:56 +0000

We explore the feasibility of combining the circulation of supercritical CO2 in EGS reservoirs with integrated gasification combined cycle (IGCC) power generation. The symbiotic benefits of this pairing increase net power output over the use of either system in isolation, reduces water use per MWe, and substantially reduces fugitive emissions over conventional thermal power plants. A prototypical plant set in the arid southwestern U.S. (environs of Albuquerque, NM) could sustain anticipated circulation rates of 800–1600 kg/s of CO2 in a 200 °C reservoir, resulting in a thermal output of 150–300 MW-thermal to augment the 550 MW from IGCC. This design would reduce annual emissions by 8,200 tons of NOx, 20,000 tons of SO2, and 4.35 million tons of CO2 over conventional thermal plants in an optimal pairing.

DOI: http://dx.doi.org/10.1021/ef301397n

All Geothermal Plants in Fukishima Region Survived Big Earthquake

A. Cherson — Sun, 23 Sep 2012 21:46:39 +0000

Japan has 16 geothermal power plants with a combined capacity of 535MW in operation. Nine plants are located in northeastern to eastern Japan, which was most affected by the earthquake. Some had to be shut down immediately after the first earthquake, but all were able to restart operation a few days after and have been providing the same electricity output as before the incident.

http://dx.doi.org/10.1016/S1755-0084(12)70091-1

NREL Releases Technology Cost and Efficiency Database for Renewables

A. Cherson — Fri, 03 Aug 2012 23:49:40 +0000

16 July 2012: The US Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL) has announced a new database, called the Transparent Cost Database (TCDB), which collects cost and performance estimates for energy efficiency and renewable energy technologies. The information is expected to facilitate corporate benchmarking, academic research and public decision making.The TCDB provides information on both historical and projected technology cost, and performance estimates for vehicles, biofuels, and electricity generation. Data have been collected from published studies and the DOE’s internal planning documents. According to NREL, the database will also soon allow experts to provide new information. The DOE’s Open Energy Information platform, a clearinghouse for energy information, will provide access to all data.

http://en.openei.org/apps/TCDB/

Rumination: What Would the Ideal ‘Green’ Home Feel and Look Like?

A. Cherson — Wed, 01 Aug 2012 20:49:48 +0000

As an experiment in green building design and clean tech implementation, I spent a couple of weekends planning, designing, modeling, and drawing two homes for environmental sustainability and self-reliance. These homes incorporate off-the-shelf technologies and green building techniques to maximize low energy, low waste, and low consumption footprints. They are also designed for interaction with nature and unique architectural interest. The video tour flies through and around the homes and ends with a listing of house systems and equipment. The Geode House (http://youtu.be/ieQ6JC7JyeM) and the Tenx House (http://youtu.be/xQ6ftwliCH0) are dedicated to my father’s memory who was a ‘green’ architect before we knew what that was.