Displaying items by tag: Solar power

Honduras: Colombia-based Grupo Argos energy subsidiary Celsia has announced that it has installed a 10.6MW solar power plant at Cementos Argos’ 1.0Mt/yr integrated Piedras Azules cement plant in Comayagua. Renewables Now News has reported that the 32,000-panel plant on the roof of the Piedras Azules plant will generate 20% of its operating power needs. Celsia says that the solar plant, its first in Honduras, will reduce Cementos Argos’ annual CO2 emissions by 10,000t/yr.

El Salvador: Switzerland-based LafargeHolcim subsidiary Holcim El Salvador has announced a planned investment of US$7.5m to establish six concrete plants in 2020, which will bring its total to 18 plants. Esmerk Latin American News has reported that the investment also covers ‘new trucks and other machinery.’ Holcim El Salvador also announced its intention ‘in the long term’ to resume operations at its 1.6Mt/yr Maya cement plant, mothballed in 2008, at an estimated cost of US$20m. It is currently investigating the possibility of installing a US$5m solar power plant at its 1.7Mt/yr El Ronco cement plant.

In 2019 Holcim El Salvador produced 1.2Mt of cement and 710,000m³ of concrete.

Cyprus: Vassiliko Cement has launched an 8MWh photovoltaic solar plant. It is located in a former quarry in the Amalas area, approximately 8km from its cement plant. The unit is expected to supply around 10% of the cement plant’s electricity requirements. The project had an investment of around Euro6.5m. The lead contractor on the project was Sunel.

Mexico: Grupo Cementos de Chihuahua (GCC) has signed a 15-year power supply agreement with a Mexico-based solar energy provider. The Awareness Times newspaper has reported that the contract covers the supply of solar power to GCC’s 0.2Mt/yr Juarez cement plant in Chihuahua, as well as its head office and ready mix and aggregates operations, constituting roughly 20% of its electricity consumption. The agreement, which enters force on 1 January 2021, will save GCC US$2.5m/yr and cut 0.3Mt of CO2 emissions throughout its duration.

US: California-based Heliogen has developed concentrated solar-thermal plants (CSPs) with the ability to focus sunlight to generate temperatures over 1000°C by micro-adjusting mirrors using computer technology. It has now engaged Parsons Corporation to build arrays of its CSPs for installation in cement pre-calciners. Requiring 900°C heat, these represent the largest part of the industry’s CO₂ output. The technology will firstly reduce this by replacing fossil fuels with a clean heat source, which moreover entirely bypasses the electrical grid. Heliogen CEO Bill Gross says that the installations will make carbon capture and storage (CCS) of the remaining CO₂ emissions from the conversion of limestone to lime easier by removing other pollutants. Heliogen is now targeting 1500°C from its CSPs, which would enable them to supersede cement fuels in kilns.

Microsoft co-founder Bill Gates entered the world of cement this week with a public relations blitz for Heliogen. He’s one of the backers of a new Californian technology startup looking to use concentrated solar power (CSP) to power heavy industrial processes like clinker or steel production. The company says it has concentrated solar energy commercially to levels above 1000°C.

Its process, called HelioMax, uses a closed-loop control system to improve the accuracy of a heliostat system. It says it achieves this by using computer vision software to better align an array of mirrors to reflect sunlight towards a single target. Temperatures of up to 1500°C is one of its targets so that it can apply itself to a variety of processes in the cement, steel, mining, petrochemical and waste treatment industries. It says it can do this for US$4.5/MCF. Another target once it hits 1500°C is to start manufacturing hydrogen or synthetic gas fuels.

Heliogen’s press release was picked up by the international press, including Global Cement, but it didn’t mention the similar work that SOLPART (Solar-Heated Reactors for Industrials Production of Reactive Particulates) project is doing in France. This project, backed by European Union Horizon 2020 funding, is developing a pilot scale high temperature (950°C) 24hr/day solar process for energy intensive non-metallic minerals’ industries like cement and lime. It’s using a 50kW solar reactor to test a fluidised bed system at the PROMES (PROcédés, Materials and Solar Energy) testing site in Odeillo, France.

Heliogen’s claim that it can beat 1000°C is significant here but it doesn’t go far enough. Clinker production requires temperatures of up to around 1450°C in the sintering phase to form the clumps of clinker. SOLPART has been only testing the calcination stage of clinker production that suits the temperature range it can achieve. Unless Heliogen can use its method to beat 1450°C then it looks likely that it will, similarly, only be able to cut fossil fuel usage in the calcination stage. If either Heliogen or SOLPART manage to do even this at the industrial scale and it is cost effective then the gains would be considerable. As well as cutting CO₂ emissions from fossil fuel usage in cement production this would reduce NO_x and SO_x emissions. It would also cut the fuel bill.

As usual this comes with some caveats. Firstly, it doesn’t touch process emissions from cement production. Decomposing limestone to make calcium oxide releases CO₂ all by itself with no fuel. About one third of cement production CO₂ emissions arise from fossil fuel usage but the remaining two thirds comes from the process emissions. However, one gain from cutting the amount of fossil fuels used is a more concentrated stream of CO₂ in the flue gas. This can potentially reduce the cost of CO₂ capture and utilisation. Secondly, concentrated solar power systems are at the mercy of the weather, particularly cloud cover. To cope with this SOLPART has been testing a storage system for hot materials to allow the process to work in a 24-hour industrial production setting.

Looking more broadly, plenty of cement producers have been building and using solar power to supply electricity. Mostly, these are photovoltaic (PV) plants but HeidelbergCement built a CSP plant in Morocco. Notably, PPC Zimbabwe said this week that it was building a solar plant to supply energy to two of its cement plants. It is doing this in order to provide a more reliable source of electricity than the local grid. India’s Birla Corporation has also said that it is buying a solar energy company today. The next step here is to try and run a cement plant kiln using electricity. This is exactly what Cementa, HeidelbergCement’s subsidiary in Sweden, and Vattenfall have been exploring as part of their CemZero project. The pilot study demonstrated that it was technically possible but only competitive compared with ‘other alternatives in order to achieve radical reductions in emissions.’

None of the above presents short or medium-term reasons for the cement industry to switch to solar power in bulk but it clearly deserves more research and, critically, funding. One particular strand to pull out here about using non-fossil fuel powered clinker production systems is that it produces purer process CO₂ emissions. Mounting carbon taxes could gradually force cement plants to capture their CO₂ but once the various technologies above become sufficiently mature they could bring this about sooner and potentially at a lower cost. In the meantime the more billionaires who take an interest in cement production the better.

India: Birla Corporation and its subsidiary RCCPL have acquired a 26% stake in AMPSolar Clean Power. The cement producer plans to buy solar power for its Raebareli cement grinding plants and its Kundanganj cement grinding plant.

Zimbabwe: PPC Zimbabwe is looking to enter into a partnership with investors to build a solar energy plant of up to 16MW to supply its two plants in Bulawayo and Colleen Bawn. It also intends to have a 28hr battery back-up facility.

The company said that the move to solar would ensure uninterrupted power supplies to its plants, which have been badly affected by the prevailing power shortages in the country. Power utility Zesa Holdings has been forced to ration power in mid 2019 as production at its main hydro-power plant dwindled due to water shortages. Its main thermal power station experiences constant breakdowns due to its old age.

Spain: Pedro Carranza, the CEO of Cementos Portland Valderrivas (CPV), has sought to reassure his company with regards to the future of the Alcalá de Guadaíara plant in Andalusia following a dispute with local authorities.

“The future of the Alcalá de Guadaíra cement plant is assured,” he said. “It is an efficient, low-cost and very well located plant in a very attractive economic environment where construction growth is above the national average. The Alcalá plant is here to stay.” Carranza added that only ‘distortion of international markets’ could compromise the plant’s future. He called for a surge in public infrastructure investment as soon as possible.

The plant has been involved in a long-running dispute with local authorities regarding co-processing of alternative fuels. A project is now underway. The plant is also exploring long-term renewable energy purchase contracts and the installation of solar panels on its site.

India: Barathi Cement has commissioned a 10MW solar power station at its 5.0Mt/yr integrated Barathi Cement Plant. The Hindu Times has reported that the facility, which spans 16.6 hectares, will partially replace combustion-derived electricity sources at the plant.