As a promising approach for sustainable development, the distributed energy system receives increasing attention worldwide and has become a key topic explored by researchers in the areas of building energy systems and smart grid. In line with this research trend, this paper presents a case study of designing an integrated distributed energy system including photovoltaics (PV), combined cooling heating and power (CCHP) and electric and thermal energy storage for commercial buildings (i.e., a hospital and a large hotel). The subsystems are modeled individually and integrated based on a proposed control strategy to meet the electric and thermal energy demand of a building. A multi-objective particle swarm optimization (PSO) is performed to determine the optimal size of each subsystem with objectives to minimize carbon dioxide emissions and payback period. The results demonstrate that the proposed method can be effectively utilized to obtain an optimized design of distributed energy systems that can minimize environmental and economic impacts for different buildings.

Access to electricity is a key necessity in today’s World for economic growth and improvements in quality of life. However, the global challenge is addressing the so-called Energy Trilemma: how to provide secure, affordable electricity while minimizing the impact of power generation on the environment. The rapid growth in power generation from intermittent renewable sources, such as wind and photovoltaics, to address the environmental aspect has created additional challenges to meet the security of supply and affordable electricity aspects of this trilemma. Fossil fuels play a major role in supporting intermittent renewable power generation, rapidly providing the security of supply needed and ensuring grid stability. Globally diesel or other fuel oils are frequently used as the primary fuel or back-up fuel for fossil-fueled power generation plants at all scales, from a few kiloWatts to hundreds of MegaWatts, and helps provide millions of people with secure electricity supplies. But diesel is a high polluting fuel, emitting high levels of carbon dioxide (CO 2 ) per unit of fuel input compared to natural gas, as well as high levels of combustion contaminants that are potentially hazardous to the local environment and human health. Additionally, diesel can be a high cost fuel in many countries, with imports consuming significant portions of sometimes scarce foreign currency reserves. Most observers consider that natural gas is the ‘fuel of choice’ for fossil power generation due to its reduced CO 2 emissions compared to coal and diesel. However, access to gas supplies cannot be guaranteed even with the increased availability of Liquefied Natural Gas (LNG) and Compressed Natural Gas (CNG). Additionally where natural gas is available, operators may opt for an interruptible gas supply contract which offers a lower tariff than a firm gas supply contract, therefore there is a need for a back-up fuel to ensure continuous power supplies. While traditionally diesel or Heavy Fuel Oil (HFO) has been used as fuel where gas is not available or as a back-up fuel, propane offers a cleaner and potentially lower cost alternative. This paper compares the potential economic, operational and environmental benefits of using propane as a fuel for gas turbine-based power plants or cogeneration plants.

Recently, cutting the CO 2 emissions has been the worldwide problem. In order to reduce the CO 2 emissions, it is important to promote the energy conservation and introduce the sustainable natural energy. In this paper, we have been studied to develop a combination energy system of the energy conservation and the natural energy in the Okayama Prefectural University. We have a result that it is possible to cut off the 36% or more CO 2 emission with the combination of (1) replacing the air-conditioner from the absorption type to a heat pump type, (2) introducing photovoltaic power generation and (3) changing the car that is used for commute from the internal-combustion engine type to an electric vehicle (EV). In addition to cut the CO 2 emission, the studied combination energy system can be presented the high economically method.

This study presents the results of an initial assessment of the technical and economic feasibility of a 5 megawatts (MW) net Solar Electric Photovoltaic (PV) power plant on the Island of Kauai, Hawaii. It analyzes three potential PV based designs of the solar power plant — single-axis tracking flat plate, fixed flat plate, and two-axis tracking concentrating photovoltaics (CPV) based on the solar insolation on Kauai. Greenhouse gas (GHG) avoided, energy production projection, capital costs, operation & maintenance (O&M) costs, and the levelized cost of energy (LCOE) of each PV design is developed for comparison. Regardless of the PV technology, the following factors may position solar PV power plant as a competitive alternative to conventional fossil-powered power plant: • Recent technology advances have occurred in concentrating solar collectors increasing overall efficiency; • Use of renewable energy can lead to reduced greenhouse gas (GHG) emissions; • Fossil fuels (e.g. natural gas and oil) retail prices are near record highs, increasing electricity rates. The assessment results show that single-axis tracking flat plate PV system are best suited for sites in Kauai as they accommodate the intermittent cloud cover of the region while following the sun from dawn until dusk as it crosses the sky.

Over the past few decades, interest in the effects of greenhouse gas (GHG) emissions on global climate change has peaked. Increasing temperatures worldwide have been blamed for numerous negative impacts on agriculture, weather, forestry, marine ecosystems, and human health. The U.S. Environmental Protection Agency reports that the primary GHG emitted in the U.S. is carbon dioxide (CO 2 ), most of which stems from fossil fuel combustion [1]. In fact, CO 2 represents approximately 85% of all GHG emissions nationwide. The other primary GHGs include nitrous oxide (N 2 O), methane (CH 4 ), ozone (O 3 ), and fluorinated gases. Since the energy sector is responsible for a majority of the GHGs released into the atmosphere, policies that address their mitigation through the production of electricity using renewable fuels and distributed generation are of significant interest. Use of renewable fuels and clean technologies to meet energy demand instead of relying on traditional electrical grid systems is expected to result in fewer CO 2 and CH 4 emissions, hence reducing global climate change impacts. Technologies considered cleaner include photovoltaics, wind turbines, and combined heat and power (CHP) devices using microturbines or internal combustion engines. The Self-Generation Incentive Program (SGIP) in California [2] provides incentives for the installation of these technologies under certain circumstances. This paper assesses the GHG emission impacts from California’s SGIP during the 2005 program year by estimating the reductions in CO 2 and CH 4 released when SGIP projects are in operation. Our analysis focuses on these emissions since these are the two GHGs characteristic of SGIP projects. Results of this analysis show that emissions of GHGs are reduced due to the SGIP. This is because projects operating under this program reduce reliance on electricity generated by conventional power plants and encourage the use of renewable fuels, such as captured waste heat and methane.

This paper presents the results of a study conducted by Itron for the California Public Utilities Commission (CPUC) to examine the relationships between solar photovoltaic (PV) performance, costs, and PV incentive structures. The intent is twofold. The first intent is to create a baseline of PV performance and costs using actual performance data and reported costs from a large number of PV systems installed and operating in California. The second intent is to examine how PV performance and projected PV cost reductions can influence PV incentive payments. This study should help provide policy makers responsible for developing PV incentive programs with information that will result in incentive structures that fairly and transparently reward improved PV cost and performance while simultaneously providing a reasonable pathway to move PV towards an incentive-free market environment. PV performance monitoring data for over one hundred operating commercial, industrial, and institutional solar PV systems are combined with projected electricity retail rates and future PV costs within a breakeven levelized cost model to produce associated PV incentive levels. Preliminary results for 39 prototype PV market scenarios provide insights into how PV incentive levels can be set to take advantage of utility-specific electricity retail rates, PV configuration and location, and projected PV cost reductions while facilitating the development of PV systems that can compete without incentives. Potential implications of these performance and cost-effectiveness results are discussed with respect to PV incentive programs and PV markets.

Developing approaches that can improve the value and “affordability” of renewable distributed generation (DG) is a key factor in developing a sustainable market. Program support activity is increasing in the U.S. in response to the 21+ states that have legislated Renewable Portfolio Standards. This paper addresses technology performance and related market entry barriers of several new innovative applications intended to increase the amount of available and harvested biogas resources, incorporate high-value applications of building-applied photovoltaics (BA-PV) and develop a more complete understanding of the impacts of these renewable DG resources upon the local electric distribution system — with the goal of achieving significantly positive net benefits to project owners/developers, their host customer facility operations, and to the serving electric and gas utilities. The overarching goal of this $10 million co-funded California Energy Commission and Commerce Energy Public Interest Energy Research Program (PIER) was to provide effective and more affordable renewable energy solutions within the Chino Basin, while applicable throughout California through specific targeted technology and market demonstrations that will lead to development of a sustainable market for on-site power generation using several types of biogas fuel and solar photovoltaic energy resources. Key outcomes resulting from the Program conclude that approximately 28 to 50 MW of PV and biogas distributed resources are expected to be developed in the nonresidential market segment alone through 2012, representing about 10 percent of Southern California Edison’s total peak load in the basin. Distribution system deferral benefits to SCE are location-specific. Up to $4.4 million in system deferral benefits may be achieved from this incremental renewable generation within the basin. Based on this first California Energy Commission-supported Programmatic RD&D approach, this paper explores the following questions: 1) How can electric grid benefits resulting from a geographically targeted renewable distributed generation effort be more fully quantified and improved? 2) Will the applications of food waste codigestion (with the local dairy waste), or ultrasound technology (applying high concentrations of sonic energy) improve waste activated sludge solids destruction and increase biogas production efficiency and onsite power generation at municipal/regional wastewater treatment facilities? 3) Can side-by-side testing and evaluation of 13 separate photovoltaic systems lead to a recommended format for an independent Consumer Reports style evaluation of the PV industry’s leaders in nonresidential and building-applied applications? These answers and other important results regarding the latest biogas and solar PV technology and their associated benefits and costs that were implemented within the 565 MVA Commerce Energy/SCE distribution system mini-grid are summarized in this paper. An overall program description and project descriptions for each biogas/PV project and associated final report documentation can be downloaded from the Commerce Energy PIER Program website at http://www.pierminigrid.org/.

Wind power offers the possibility of onsite generation of renewable energy for residential, commercial and industrial energy users in urban and suburban areas. This form of electricity production has generally been limited to rural and utility applications, but continued improvements have generated new interest in the potential of wind power in urban environments. There are several key elements that determine the viability of urban wind power, the most important of which are turbine technology, wind resources, costs and regulations. This paper will examine these elements with the goal of assessing the current status and future potential of urban wind power. Urban environments present a unique set of challenges to wind power, which demand turbine technology specific to these applications. Buildings create turbulent wind patterns, destroying the constant, steady winds on which utility scale turbines are dependant. Noise, shadow and vibration due to turbines is more important in urban applications, and turbine esthetics becomes a major focus. A new generation of wind turbines is now being produced with these concerns specifically in mind. There are a variety of solutions to these problems, which designers are beginning to explore. An essential element in the success of a turbine is the availability of wind resources. New turbine designs are being produced to utilize lower velocity winds. Additionally, engineers and architects can create better turbine locations through the integration of turbines with building design. Through this integrated design, buildings can contribute to the wind resources by increasing wind speeds and directing wind through the turbine. Available wind and turbulence, along with the characteristics of the particular turbine design, dictates how much electricity can be produced. The third critical aspect of urban wind power is the cost of producing electricity. To gain success, urban wind generators must be cost competitive with other urban applications of renewable energy technologies. The primary competition in this market is from solar photovoltaics, which currently produce power at about 50 ct/kWh. Utility scale wind turbines are not part of this market, and therefore do not compete with urban turbines. Urban turbines have the potential to produce electricity at costs of down to 10 ct/kWh. Future technology improvements, along with increased production, could significantly reduce the capital cost and further reduce the price of generating power. There are also opportunities for tax incentives, feed-in tariffs and other subsidies that can reduce the installed cost of wind power. Finally, regulations and policy can be a major obstacle to urban wind power. This includes zoning and building codes, as well as electronics certifications and interconnection regulations. This paper will examine existing and future turbine technologies, urban wind resource availability and the costs associated with producing energy via urban wind power. It will also identify roadblocks to the implementation and assess the overall viability of this type of renewable energy production.

About 2 billion people of the world, mostly in rural areas of the developing countries, do not have access to grid-based electricity. The most critical factor affecting their livelihoods is access to clean, affordable and reliable energy services for household and productive uses. Under this backdrop, renewable and readily available energy from the nature can be incorporated in several proven renewable energy technology (RET) systems and can play a significant role in meeting crucial energy needs in these remote far flung areas. RETs are ideal as distributed energy source and they can be incorporated in packages of energy services and thus offer unique opportunities to provide improved lighting, health care, drinking water, education, communication, and irrigation. Energy is also vital for most of the income-generating activities, both at the household or commercial levels. Access to energy is strongly connected to the achievement of the Millennium Development Goals (MDGs), which set targets for poverty reduction, improved health, and gender equality as well as environmental sustainability. Environmentally benign renewable energy systems can contribute significantly in the above-mentioned unserved or underserved areas in the developing countries to achieve both local and global environmental benefits. This is important in the context of sustainable development in: (i) poverty alleviation, (ii) education, (iii) gender equity and empowerment, (iv) health including other benefits like improved information access through Information and Communication Technology (ICT) centers, (v) better security, and (vi) increase in social or recreational opportunities. It is evident that proliferation of renewable energy resources through implementing their applications for meeting energy demand will promote all the three dimensions namely, social, economic and environmental of sustainable development in the developing countries. Several small scale enabling RET systems have been suggested in this paper in the light of above-mentioned issues of energy sustainability and they can significantly contribute to the improvement of the livelihood of the remote impoverished rural communities of the developing countries. With the current state of technology development, several RET systems (such as wind, solar photovoltaics, solar thermal, biomass and microhydro) have become successful in different parts of the world. In this paper, an exhaustive literature survey has been conducted and several successful and financially viable small-scale RET systems were analyzed. These systems have relevance to the economies of the developing countries that can be utilized for electrification of domestic houses, micro enterprises, health clinics, educational establishments and rural development centers.

People in the developing countries who lack basic services and economic opportunities are primarily concerned with improving their living conditions. At present, unemployment problem in the rural areas of the developing countries are diversifying the moral values and social responsibilities of unemployed youth. To solve the problem, rural development centres (involving vocational training, IT services and other productive activities) can contribute significantly for the upliftment of these rural youths and can transform them into grass-root entrepreneurs. One critical factor hindering the establishment of such rural development centers is access to affordable and reliable energy services. Under this backdrop, environmentally benign renewable energy systems can contribute significantly in providing much needed energy in the unserved or underserved rural development centers in the developing countries to achieve both local and global environmental benefits. The paper demonstrates that energy deficient, economically backward communities in the off-grid areas of the developing countries, can be given an array of opportunities for income generation and social progress through rural development centers with the aid of renewable energy sources (such as wind, solar photovoltaics, solar thermal, biomass and micro-hydro), thereby improving their standard of living. Poverty alleviation in rural areas can be accomplished and the critical role of access to adequate level of energy services, Information Technology (IT) and modern communication facilities in it demonstrated. Furthermore, the production, implementation, operation and maintenance of renewable energy applications being labor-intensive, will also result in job growth in the village context, preventing migration of labor force, especially of young men, from rural areas to overcrowded industrial areas. An appropriately designed renewable energy systems can also have a significant role in reducing the impact of climate change through non production of green house gases.