![]() ![]() This environmental benefit comes at a cost of US$0.68 trillion in net first costs (including installation and replacement costs), and US$0.27 trillion in lifetime net operations savings. Scenario 1 shows a total greenhouse gas reduction of 3.41 gigatons of carbon dioxide-equivalent emissions. ResultsĪll monetary values are presented in 2014 US$. We calculated the impact on building energy demand for highest-priority solutions and reduced energy-related input values for the Solar Hot Water solution to represent the impact of higher-priority building envelope solutions.Īlthough we used the term “priority,” we do not mean to say that any solution was of greater importance than any other, but rather that for estimating total impact of all building solutions, we simply applied the impacts of some solutions before others, and used the output energy demand after application of a higher-priority solution as the energy demand input to a lower-priority solution. This meant that building envelope solutions like Insulation were first, building systems like Building Automation Systems were second, and building applications like High-Efficiency Heat Pumps were last. We integrated the Solar Hot Water solution with others in the Buildings sector by first prioritizing all solutions according to the point of impact on building energy usage. Emissions calculations used emissions factors from the guidelines of the Intergovernmental Panel on Climate Change (IPCC). The ongoing annual costs are represented by the fuel and fixed and variable operating costs. The first cost was an average of 41 data points from the International Energy Agency (IEA), Renewable Energy Policy Network for the 21st Century (REN21, 2018), and other sources. This is a conservative assumption, but it accommodates the need to provide backup systems with as much heating power as needed by households. We assumed that solar hot water systems would supplement existing electric and gas heaters, not replace them. The emissions included in this work cover electricity and fuel for conventional heating of water, electricity for pumping of water in solar hot water systems, and indirect emissions from construction of the water heating systems. ![]() A second-order polynomial curve is fit to those points to create a smooth curve. Scenario 2: This scenario assumes that 1,886.52 terawatt-hours of solar hot water (30 percent of the total total addressable market) are adopted in 2050 and 45 percent of that would be adopted by 2030.Scenario 1: This scenario assumes that 799.11 terawatt-hours of solar hot water (15 percent of the total total addressable market) are adopted in 2050, and 50 percent of that would be adopted by 2030.We calculated impacts of increased adoption of solar hot water from 2020 to 2050 by comparing two scenarios with a reference scenario in which the market share was fixed at current levels. It amounted to 5,400 terawatt-hour (therms) in 2018. We estimated it using data from several sources, including the International Energy Agency (IEA) and Global Buildings Performance Network. We defined the total addressable market for solar hot water as the amount of water heating demanded by residences worldwide. Data suggest that 8 percent of the total had already adopted solar water heating by 2018 with a heavy concentration in China. Solar hot water systems can be differentiated by the type of solar thermal collector used (unglazed and glazed flat plate collectors and evacuated tube collectors) and the type of system operation (active, which have circulating pumps and controls, and passive, which do not). Solar hot water is also used in commercial buildings, but we do not include this application here. This solution replaces conventional fossil fuel-based water heating. Project Drawdown’s Solar Hot Water solution involves the use of solar radiation to preheat or heat water for residential use. Solar water heating-exposing water to the sun to warm it-can reduce that fuel consumption. Heating water for showers, laundry, and washing dishes accounts for a quarter of residential energy use worldwide. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |