Optimization of the design of polygeneration systems for the residential sector under different self‐consumption regulations

Abstract

Polygeneration systems enable natural resources to be exploited efficiently, decreasing CO 2 emissions and achieving economic savings relative to the conventional separate production. However, their economic feasibility depends on the legal framework. Preliminary design of polygeneration systems for the residential sector based on the last Spanish self-consumption regulations RD 900/2015 and RD 244/2019 was carried out in Zaragoza, Spain. Both regulations were applied to individual and collective installations. Several technologies, appropriate for the energy supply to residential buildings, for example, photovoltaics, wind turbines, solar thermal collectors, microcogeneration engines, heat pump, gas boiler, absorption chiller, and thermal and electric energy storage were considered candidate technologies for the polygeneration system. A mixed integer linear programming model was developed to minimize the total annual cost of polygeneration systems. Scenarios with and without electricity sale were considered. CO 2 emissions were also calculated to estimate the environmental impact. Results show that RD 900/2015 discourages the investment in self-consumption systems whereas the RD 244/2019 encourages them, especially in renewable energy technologies. Moreover, in economic terms, it is more profitable to invest in collective self-consumption installations over individual installations. However, this does not necessarily represent a significant reduction of CO 2 emissions with respect to individual installations since the natural gas consumption tends to increase as its unit price decreases because of the increase of its consumption level. Thus, more appropriate pricing of natural gas in residential sector, in which its cost would not be reduced when increasing its consumption, would be required to achieve significant CO 2 emissions reduction. In all cases, the photovoltaic panels (PV) are competitive and profitable without subsidies in self-consumption schemes and the reversible heat pump (HP) played an important role for the CO 2 emissions reduction. In a horizon to achieve zero CO 2 emissions, the net metering scheme could be an interesting and profitable alternative to be considered.

A Novel Polygeneration System Based on a Solar-Assisted Desiccant Cooling System for Residential Buildings: An Energy and Environmental Analysis

“…However, as an economic analysis of this study was not performed, a deep discussion on pricing policies was neglected. Detailed analysis on residential sector regulation in Spain is reported by Pinto et al [32].…”

Assessing the influence of legal constraints on the integration of renewable energy technologies in polygeneration systems for buildings

“…Schütz et al [53] proposed an optimization model for the design, sizing and operation of energy systems supplying electricity and heat to residential buildings with a precise modelling of many specific German regulations, such as feed-in limitation and remuneration, levies, tax exemptions, subsidies, among others. Pinto et al [54] presented a detailed synthesis model for CCHP systems in residential buildings including PV and wind turbines and used the model to compare different Spanish grid regulations.…”

Modelling of Consumption Shares for Small Wind Energy Prosumers

“…With the addition of the storage device, the self-consumption of wind energy increased by almost 10% [27]. In Spain, different energy generation systems based on solar PV are competitive and profitable without subsidies in self-consumption schemes [28]. In fact, the setting up of distributed generation, when exploited in a self-sufficiency manner, may decrease the utilisation peaks [29].…”