Displaying items by tag: Solar power

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.

Pakistan: Fauji Cement has installed a 12.5MW solar power plant at its Jhang Bahtar plant, near Islamabad. Business Recorder reports that Fauji’s is the world’s largest solar power station devoted to a cement plant, with 37,905 panels delivering an estimated annual total of 19,750MWh of energy.

Fauji has additionally installed two waste heat recovery plants of 12 and 9MW and two large reservoirs for water recycling and rainwater harvesting. Fauji is leading Pakistans’s Clean and Green initiative, having planted 25,000 trees and donated a further 40,000 plants to local government and nearby villages.

Togo: HeidelbergCement is considering investments of up to Euro25m in its local subsidiaries including Cimtogo, Scantogo and Granutogo. Local director general of the company Eric Goulignac outlined the plans, including building and installing a new mill at Cimtogo’s cement grinding plant in Lomé and a photvoltaic (PV) solar energy plant, according to the All Africa news agency. The projects will be considered by the board of HeidelbergCement in the summer before a final decision is made.

France/Thailand: SCG Cement has signed a Memorandum of Understanding with France’s Constant Energy to build 50MW of solar photovoltaic (PV) units at its plants and associated companies. The target is to deploy and commission the solar PV plants over the next three years, through rooftop-based, ground-mounted and floating solar PV plants. Engineering of a first solar PV plants has started and the pre-construction permitting and licensing process will be handled in the second quarter of 2019, followed by construction.