The gas supply can be abbreviated as P2G or PtG. This means that the electrolysis of water mainly alkaline electrolysis, proton exchange membrane electrolysis (PEM), solid oxide electrolysis cell (SOEC) is a method of converting renewable energy as a vector of gaseous energy Like hydrogen and methane In other words, the electrochemical process breaks down water into hydrogen and oxygen and then converts it to methane so that hydrogen reacts with the dioxide carbon in the presence of a biocatalyst. The generated green hydrogen can be used in different ways to power outages and provide the industry with new sources of revenue by separating the production of renewable energy from the demand for electricity.
It can be stored and reused as a fuel to generate energy from gas turbines or fuel cells and can store large amounts of fuel compared to the current battery accumulator. Longer energy. However, it can also be injected into the natural gas grid with some restrictions because too high hydrogen content can cause technical and safety problems. The UK only allows hydrogen injection at 0.1% by volume, while in some parts of the Netherlands the limit is 12%. However, work is underway to reduce these restrictions. In November 2018 a project led by British HyDeploy and involving Northern Gas Networks with progressive and electrolytic energy supplier ITM Power started a one-year trial period to explore green hydrogen injection up to 20%.
When converted to synthetic methane, the gas can be used as a direct replacement for fossil natural gas in the natural gas network or as a seasonal energy storage. This is important because, as noted by the Oxford Energy Institute in the P2G file in October 2018, it is possible to introduce considerable flexibility in the energy system, which will lead to a more tightly integrated coupled natural gas and power system Prices may be cheaper than full electrification of natural gas.
Martin Therma, F, an expert from the University of Applied Sciences and Technology (OTH) in Regensburg, Germany. Bauer and M. Sterner pointed out that since 1988, about 143 P2G projects have been put into operation in 1988. 22 countries. In 2019, only 56 hydrogen projects and 38 methanation projects were active. Although the existing fleet mainly includes pilot or demonstration projects below 1 MW, nearly 45% of these projects feed or plan to feed natural gas into the grid or convert it into electricity or heat.
To date, 64 projects have been installed in Germany, followed by Denmark, the United Kingdom, France, the United States, Switzerland, Spain, Canada and Japan. The location is important because the choice often depends on the requirements of the integrated energy system, such as the hydrogen resistance of the gas network, gas damping, fluidity and thermal applications. Experts explained in an article published in the Renewable and Sustainable Energy Review in September this year.
Recently, as more and more people discuss the role of P2G in the development of future energy systems and technologies, several larger and more ambitious projects are being planned. OTH experts point out, even though many projects today are pilot plants with a life span of 1-3 years and still require funding, medium- and long-term plans are still being implemented on a large scale, and more and more projects are designed to run for 10 years.
Another driver is the reduction in the cost of electrolytic technology. According to the International Energy Agency (IEA), electrolytic cells account for 50% and 60% of the capital expenditure (CAPEX) costs of alkaline electrolytic cells and PEM electrolytic cells, respectively, while power electronics, gas conditioning, and plant components account for most of the remaining. Today, CAPEX requirements for alkaline electrolytic cells range from $ 500 to $ 1,400 / kWe. PEM electrolyzers cost between $ 1,100 and $ 1,800 / kWe. The cost of SOEC is estimated at $ 2,800 to $ 5,600 per kilowatt. OTH experts predict that the cost of high-temperature electrolysis may plummet by 85% by 2050. In response to the IEA, experts attribute the future cost reduction to increased automation, economies of scale, production capacity, and technological advances.
As pointed out by Oxford College, the massive use of water is another P2G challenge. An analysis of the life cycle of water consumption required for hydrogen production indicates that about 10 gallons (38 kg) of water per kilogram of hydrogen produced by electrolysis are needed. It is said. Position constraints are perhaps the most important. Even its conversion efficiency is a big obstacle. It is stated that in the early stages of deployment, P2G chains will generate significant system losses and overall conversion efficiency (i-e, energy production as a percentage of energy input)). The company stated that, broadly speaking, the conversion efficiency of hydrogen produced by P2G is between 50% and 75% and that the addition of an anaerobic digestion phase would reduce the efficiency by about 10 points percentages. With the evolution of technology, thanks to technological advances, conversion efficiency can also be significantly improved in the long run.
Despite the high costs and current conversion losses, the exponential development of technologies that involve costs on the one hand and installed capacity on the other shows that the implementation of [natural gas-electricity] on the market is underway, which is the conclusion designed by OTH experts. P2G can also offer the added benefit of providing seasonal storage to help balance power systems that increasingly use intermittent renewable energy sources.