This conference is composed of 15 communications concerning cogeneration systems and applications in local communities. The main themes are: the regulation context and administrative procedures for cogeneration projects in France; legal aspects, risk covering, financing and sellback conditions for cogeneration systems; examples of cogeneration and tri-generation (with refrigeration energy) in different cities, airport, hospitals, campus, combined with the upgrading of district heating systems or municipal waste incineration plants. Impacts on energy savings and air pollution are also discussed
The rate of return of the combined generation of heat and power is not only determined by the capital expenditures and the costs of maintenance, control, management and insurance, but also by the fuel costs of the cogeneration installation and the avoided fuel costs in case of separated heat production, the avoided/saved costs of electricity purchase, and the compensation for possible supply to the public grid (sellback). This brochure aims at providing information about the structure of natural gas and electricity tariffs to be able to determine the three last-mentioned expenditures. First, attention is paid to the tariffs of natural gas for large-scale consumers, the tariff for cogeneration and horticulture, and natural gas supply contracts. Next, the structure of the electricity tariffs is dealt with in detail, discussing the accounting system within the electric power sector, the tariffs and compensations for large-scale consumers and specific large-scale consumers, electricity sellback tariffs, and compensations for reserve capacity. Also attention will be paid to tariffs for electricity transport. Finally, several taxes, excises and levies that have a direct or indirect impact on natural gas tariffs, are discussed. 9 refs
Van Zuylen, E.J.; Van Wijk, A.J.M.
In the European countries different methods are used to stimulate renewable energy, in particular wind energy. In the Netherlands use is made of investment subsidies to install wind turbines on a large scale. In other countries (in this report Denmark, Germany, Great Britain and a few other countries) mainly use is made of the sellback method: electricity, generated by the wind turbines, is supplied to the grid. Also a combination of investment subsidies and sellback is applied. An overview is given of the financial incentive regulations in the above-mentioned countries. Also attention is paid to the underlying motivation and argumentation for the subsidies, the relation between wind energy subsidies and subsidies for other decentralized power generating options, and the impact of the European Union regulations in this matter. Finally an indication is given of how the regulations are financed: out of the general fund, out of environmental levies or directly from the electric companies. Most of the data presented in this report are the results of interviews with representatives of the different countries. 8 tabs
The rate of return of the combined generation of heat and power is not only determined by the capital expenditures and the costs of maintenance, control, management and insurances, but also by the fuel costs of the cogeneration installation and the avoided fuel costs in case of separated heat production, the avoided/saved costs of electricity purchase, and the compensation for possible supply to the public grid (sellback). This brochure aims at providing information about the structure of natural gas and electricity tariffs to be able to determine the three last-mentioned expenditures. First, attention is paid to the tariffs of natural gas for large-scale consumers, the tariff for cogeneration, and other tariffs. Next, the structure of the electricity tariffs is dealt with in detail, discussing the accounting system within the electric power sector, including the alterations in the National Basic Tariff and the Regional Basic Tariff (abbreviated in Dutch LBR, respectively RBT) per January 1, 1995, the compensations for large-scale consumers and specific large-scale consumers, electricity sellback tariffs, and compensations for reserve capacity. 7 figs., 5 tabs., 2 appendices, 7 refs
Three more or less reliable methods to determine the financial acceptance of the external effects of the use of wind energy are discussed. Attention is paid to the appreciation of external effects based on the environmental pollution or damage, appreciation based on prevented costs (implied valuation), and appreciation based on surveys, by which the willingness of the civilians to pay for a clean environment can be determined. A first indication of the environmental benefits of wind energy based on the above-mentioned methods is 0.04 to 0.08 DFl per kWh. For the total service life of a wind turbine this amounts to 800-1600 DFl per kW. The environmental benefits can be re-calculated in the form of subsidies, increasing the sellback prices or by means of an environmental levy on electric power generated by conventional power plants. 2 figs., 1 tab., 12 refs
Full Text Available Due to the intermittent nature, renewable energy sources (RES has brought new challenges on load balancing and energy dispatching to the Smart Grid. Potentially served as distributed energy storage, Electric Vehicle’s (EV battery can be used as a way to help mitigate the pressure of fluctuation brought by RES and reinforce the stability of power systems. This paper gives a comprehensive review of the current situation of EV technology and mainly emphasizing three EV discharging operations which are Vehicle to Grid (V2G, Vehicle to Home (V2H, and Vehicle to Building (V2B, respectively. When needed, EV’s battery can discharge and send its surplus energy back to power grid, residential homes, or buildings. Based on our data analysis, we argue that V2G with the largest transmission power losses is potentially less efficient compared with the other two modes. We show that the residential users have the incentive to schedule the charging, V2G, and V2H according to the real-time price (RTP and the market sell-back price. In addition, we discuss some challenges and potential risks resulting from EVs’ fast growth. Finally we propose some suggestions on future power systems and also argue that some incentives or rewards need to be provided to motivate EV owners to behave in the best interests of the overall power systems.
Borden, C. S.
Utility-interactive photovoltaic (PV) arrays on residential rooftops appear to be a potentially attractive, large-scale application of PV technology. Results of a comprehensive assessment of the value (i.e., break-even cost) of utility-grid connected residential photovoltaic power systems under a variety of technological and economic assumptions are presented. A wide range of allowable PV system costs are calculated for small (4.34 kW (p) sub ac) residential PV systems in various locales across the United States. Primary factor in this variation are differences in local weather conditions, utility-specific electric generation capacity, fuel types, and customer-load profiles that effect purchase and sell-back rates, and non-uniform state tax considerations. Additional results from this analysis are: locations having the highest insolation values are not necessary the most economically attractive sites; residential PV systems connected in parallel to the utility demonstrate high percentages of energy sold back to the grid, and owner financial and tax assumptions cause large variations in break-even costs. Significant cost reduction and aggressive resolution of potential institutional impediments (e.g., liability, standards, metering, and technical integration) are required for a residential PV marker to become a major electric-grid-connected energy-generation source.
She, Ying; Erdem, Ergin; Shi, Jing
Residential wind turbines are often accompanied by an energy storage system for the off-the-grid users, instead of the on-the-grid users, to reduce the risk of black-out. In this paper, we argue that residential wind turbines with battery energy storage could actually be beneficial to the on-the-grid users as well in terms of monetary gain from differential pricing for buying electricity from the grid and the ability to sell electricity back to the grid. We develop a mixed-integer linear programming model to maximize the profit of a residential wind turbine system while meeting the daily household electricity consumption. A case study is designed to investigate the effects of differential pricing schemes and sell-back schemes on the economic output of a 2-kW wind turbine with lithium battery storage. Overall, based on the current settings in California, a residential wind turbine with battery storage carries more economical benefits than the wind turbine alone.
Simpkins, T.; Cutler, D.; Anderson, K.; Olis, D.; Elgqvist, E.; Callahan, M.; Walker, A.
REopt is NREL's energy planning platform offering concurrent, multi-technology integration and optimization capabilities to help clients meet their cost savings and energy performance goals. The REopt platform provides techno-economic decision-support analysis throughout the energy planning process, from agency-level screening and macro planning to project development to energy asset operation. REopt employs an integrated approach to optimizing a site?s energy costs by considering electricity and thermal consumption, resource availability, complex tariff structures including time-of-use, demand and sell-back rates, incentives, net-metering, and interconnection limits. Formulated as a mixed integer linear program, REopt recommends an optimally-sized mix of conventional and renewable energy, and energy storage technologies; estimates the net present value associated with implementing those technologies; and provides the cost-optimal dispatch strategy for operating them at maximum economic efficiency. The REopt platform can be customized to address a variety of energy optimization scenarios including policy, microgrid, and operational energy applications. This paper presents the REopt techno-economic model along with two examples of recently completed analysis projects.
Soshinskaya, Mariya; Crijns-Graus, Wina H.J.; Meer, Jos van der; Guerrero, Josep M.
Highlights: • Research assesses application of renewable microgrid for Dutch water treatment plant. • Grid-connected and stand-alone cases are modeled with and without demand response. • Results show a high potential for wind and solar electricity generation at the site. • The plant can become 70–96% self-sufficient with renewable electricity. • A grid connected system with both wind, PV and demand response is most cost-effective. - Abstract: This research explores the techno-economic potential for a predominantly renewable electricity-based microgrid serving an industrial-sized drink water plant in the Netherlands. Grid-connected and stand-alone microgrid scenarios were modeled, utilizing measured wind speed and solar irradiation data, real time manufacturer data for technology components, and a bottom-up approach to model a flexible demand from demand response. The modeled results show that there is a very high potential for renewable electricity at the site, which can make this drink water treatment plant’s electricity consumption between 70% and 96% self-sufficient with renewable electricity from solar PV and wind power production. The results show that wind production potential is very high onsite and can meet 82% of onsite demand without adding solar PV. However, PV production potential is also substantial and provides a more balanced supply which can supply electricity at times when wind production is insufficient. Due to the supplemental supply over different parts of the day, adding solar PV also increases the benefits gained from the demand response strategy. Therefore, a solar–wind system combination is recommended over a wind only system. A 100% renewable system would require extremely large battery storage, which is not currently cost effective. Ultimately, even at the low wholesale electricity and sell-back price for large electricity consumers, grid-connection and the ability to trade excess electricity is extremely important for the
Borden, C. S.
The Lifetime Cost and Performance (LCP) Model was developed to assist in the assessment of Photovoltaic (PV) system design options. LCP is a simulation of the performance, cost, and revenue streams associated with distributed PV power systems. LCP provides the user with substantial flexibility in specifying the technical and economic environment of the PV application. User-specified input parameters are available to describe PV system characteristics, site climatic conditions, utility purchase and sellback rate structures, discount and escalation rates, construction timing, and lifetime of the system. Such details as PV array orientation and tilt angle, PV module and balance-of-system performance attributes, and the mode of utility interconnection are user-specified. LCP assumes that the distributed PV system is utility grid interactive without dedicated electrical storage. In combination with a suitable economic model, LCP can provide an estimate of the expected net present worth of a PV system to the owner, as compared to electricity purchased from a utility grid. Similarly, LCP might be used to perform sensitivity analyses to identify those PV system parameters having significant impact on net worth. The user describes the PV system configuration to LCP via the basic electrical components. The module is the smallest entity in the PV system which is modeled. A PV module is defined in the simulation by its short circuit current, which varies over the system lifetime due to degradation and failure. Modules are wired in series to form a branch circuit. Bypass diodes are allowed between modules in the branch circuits. Branch circuits are then connected in parallel to form a bus. A collection of buses is connected in parallel to form an increment to capacity of the system. By choosing the appropriate series-parallel wiring design, the user can specify the current, voltage, and reliability characteristics of the system. LCP simulation of system performance is site