Displaying items by tag: Solar power
There is lots to mull over for the cement industry from last week’s Global Slag Conference that took place in Prague.
One striking map from Michael Connolly, TMS International, showed the status of slag and steel products in the US. It was a multi-coloured patchwork of different regulatory statuses from approval to be used as a product to regulatory exclusion. This won’t come as a surprise to many readers but even within one country the way slag can be used legally varies.
As this column reported last year after the Euroslag Conference, the European Union can be presented in a similar way. The irony here is that increased use of slag and other secondary cementitious materials (SCM) is exactly the kind of change the cement and concrete industries need to make to decrease their carbon emissions. Constant quibbles over whether slag is a product or a waste undermine this. Happily then that Connolly was able to report progress in the US as lobbying by industry and the US National Slag Association have led to more states legally accepting slag as a product.
However, cement producers have other concerns in addition to environmental ones when it comes to slag usage as Doug Haynes from Smithers Apex explained. Haynes, a former UK steel industry worker turned consultant, spoke around a market report on the future of ferrous slag. His take on Basic Oxygen Furnace (BOF) slag was that despite fuel savings, decreased CO2 emissions and the benefits of embodied iron when it is used as a raw material for clinker production, it is in the interests of cement producers for slag to be a waste because they then get it for free or at a reduced rate. It’s a similar story to the use of waste-derived fuels powering cement plant kilns where producers want lower fuel costs but waste collectors want value for their product. Unsurprisingly, Haynes wanted cement producers to accept the value embodied in BOF slag.
Charles Zeynel of ZAG International, an SCM trader, then laid out the situation where global SCM supplies are remaining static but cement demand is growing. Coal-fired power station closures are reducing supplies of fly ash, another SCM, placing pressure on existing granulated blast furnace slag (GBS) slag supplies. The message was very much in a slag trader’s favour but instructive nethertheless. If slag is in demand then the price will rise. Anecdotally, the increased number of cement producers at the conference seemed to indicate increased interest of the cement industry in the product.
Lots more speakers followed on topics such as slag beneficiation, grinding advances and new innovations. On grinding, one surprise that popped up was that Spain’s Cemengal has sold a Plug & Grind Vertical mill to CRH Tarmac’s cement plant at Dunbar in Scotland. It is the first such sale of this product in Europe. The last speaker, Jürgen Haunstetter of the German Aerospace Centre, stuck out particularly with his presentation on using slag as a thermal energy storage medium in a concentrated solar power (CSP) plant. This may not seem connected to the cement industry but it is along similar lines to Italcementi’s project at the Aït Baha cement plant in Morocco, which uses a CSP process that can be used with the plant’s waste heat recovery unit.
The Global Slag Conference will return in April 2019 in Aachen, Germany.
Read the full review of the 13th Global Slag Conference 2018
Egypt: Titan Cement Egypt is planning to spend US$8m towards building a 8MW solar power plant next to its Beni Suef cement plant. Surplus energy from the unit will be sold to the national grid, according to the Al Borsa newspaper. The project is at the bidding stage with contractors but the cement producer is believed to be in ‘advanced talks’ KarmSolar.
Iran: Austria’s Fronius Solar Energy has installed an inverter for the 1.5MW photovoltaic solar plant at Shahrekord Cement Company’s plant. The engineering firm supplied its Fronius Symo 76 product for the site situated at 2300m above sea level that experiences a wide variation in ambient temperature between -10°C and 50°C. Using this system, the cement producer has achieved a total yield of 2953MWhr/yr, which it feeds back to the grid. The operator is also able to monitor the system using the Fronius Solar web analysis tool and it is using the provider’s Service Partner programme for ongoing support.
Sun shines on the cement industry
03 January 2018Just before the Christmas break one of the Global Cement editorial staff noticed how many solar projects have been popping up in the industry news of late. Looking at stories on the Global Cement website tagged with ‘solar’ five occurred in a six month period of 2017 out of a total of 13 since 2014. It’s not a rigorous study by any means but projects in the US, South Korea, India, Namibia and Jordan all suggest a trend.
All these new projects appear to be providing a supplementary energy source from photovoltaic (PV) solar plants that will be used to supply a portion of a cement plant’s electrical power requirements at a subsidised cost. Typically, these initiatives are preparing to supply 20 - 30% of a plant’s electricity over a couple of decades. These schemes are often supported by government subsidies to encourage decarbonised energy sources and a general trend in societies for so-called ‘greener’ energy sources in the wake of the Paris agreement on climate change.
Global Cement is familiar with this model of solar power in the cement industry from its use at the HeidelbergCement Hanson plant at Ketton in the UK. The project was realised by Armstrong Energy through local supplier Lark Energy and it provides around 13% of the cement plant’s electrical energy needs. Originally the array started off by supplying 10MW but this was later increased to 13MW in 2015. A key feature is that as part of the agreement with Armstrong Energy, Hanson receives 35% of the solar power generated for free and buys the remaining 65% at a fixed rate. Even at this rate the plant expects to save around Euro11m in energy costs over the lifetime of the solar array. In addition it will save 3500t/yr of CO2.
Most of the new solar projects announced in 2017 are of a similar scale and ambition to what Hanson Cement has done at Ketton. However, JSW Group’s plans are a magnitude larger. The Indian cement producer wants to build a 200MW solar plant next to its cement grinding plant at Salboni in West Bengal for US$124m. However, it has hedged its bets somewhat by saying that it might build a 36MW thermal power plant instead if its proposal fails.
LafargeHolcim and Italcementi have also experimented with concentrated solar power (CSP) plants for the cement industry. In 2007 LafargeHolcim and the Solar Technology Laboratory of the Paul Scherrer Institute and the Professorship of Renewable Energy Carriers at ETH Zurich started researching using high-temperature solar heat to upgrade low-grade carbonaceous feedstock to produce synthetic gas. The intention was to use the synthetic gas as a substitute for coal and petcoke in kilns.
Italcementi’s project at the Aït Baha plant in Morocco uses a CSP process that can be used with the plant’s waste heat recovery unit. Its moveable trough-style solar collectors follow the sun throughout the day to warm up a heat-transfer fluid during the day and store the heat in gravel beds overnight. In this way the CSP process allows for continuous operation over 24 hours. Before Italcementi’s acquisition by HeidelbergCement in 2016 the company had long-term ambitions to roll-out its CSP process across plants in the Middle East and North African region.
New battery technology of the kind backing the growing electric car industry may be further pushing the cement industry’s preference to PV over CSP power. The other renewable energy source slowly being built to support cement plants has been wind. Like PV it too suffers from cyclical disruptions to its power. Technological entrepreneur Elon Musk (of Tesla car fame) notably supplied the world's largest lithium-ion battery to Southern Australia to support one of its wind farms in late 2017. Around the same time local cement producer Adelaide Bighton announced in a separate deal that it had struck a deal to use wind power to part-power some of its facilities in the same region. At present it doesn’t look like solar power will be completely powering cement plants in the near future but perhaps a renewable fuels rate along similar lines to an alternative fuels rate might be a growing trend to watch.
The Global Cement CemPower conference on electrical power, including waste heat recovery, captive power, grinding optimisation and electrical energy efficiency, will return in January 2019.
Adelaide Brighton to use green power
28 November 2017Australia: Adelaide Brighton will power some of its facilities with electricity from a 278.5MW wind farm owned by Infigen Energy, according to the Australian Financial Review. Adelaide Brighton will use the electricity to supply two of its cement plants near Adelaide, South Australia, and a quarry on Yorke Peninsula.
The two companies have signed a contract that calls for the cement manufacturer to buy power from the Lake Bonney wind farm for a five-year term. Specific terms of the deal have not been provided, while the contracted amount is said to be more than the 88GWh that were contracted in a bulk power purchase agreement (PPA) deal for a wind project in Melbourne earlier in November 2017.
Holcim US proposes solar unit for Hagerstown cement plant
11 September 2017US: Holcim US has proposed a 10MW solar unit for its Hagerstown cement plant in Maryland. NRG Solar Hagerstown, a subsidiary of NRG Energy, will build the array and lease the site for 35 years, according to Herald-Mail Media. The solar unit could meet up to 20% of the plant’s annual power requirements and the project is expected to last for at least 20 years. Construction is scheduled to start in the second quarter of 2018 and it is planned to last up to five months. No value for the project has been disclosed.
Hyundai Cement plans solar plant at Danyang plant
25 August 2017South Korea: Hanil Cement and LK Investment Partners are considering plans to build a solar plant at Hyundai Cement’s plant at Danyang. The owners of the cement plant want to build the solar plant at the site when its limestone reserves start to decline, according to the Maeil Business Newspaper. The new power plant is intended to increase its profitability.
India: JSW Group is considering plans to build a 200MW solar plant next to its cement grinding plant at Salboni in West Bengal. The owner of JSW Cement is considering plans for land it owns at the site, according to the Press Trust of India. The group says it is in advanced talks with foreign contractors to build the US$124m project. However, if the proposal fails it will build a 36MW thermal power plant instead for use by the cement plant.
Ohorongo Cement preparing to build solar plant
08 June 2017Namibia: Ohorongo Cement has held a ground breaking ceremony for a 5MW solar plant at its Sargberg cement plant in North Otavi. The site is being developed and built by Germany’s SunEQ and its local partner Hungileni. The US$7.8m project is scheduled to start operation by the end of 2017.
“Electricity is of paramount importance to our operations and constitutes 25% of our production requirements. We are aware of the country’s precarious energy situation and hence took the decision to tap into the renewable energy resource which our country is endowed with,” said Hans-Wilhelm Schutte, Ohorongo Cement’s managing director.
Ohorongo Cement has signed a 15-year power purchase agreement with SunEQ. Construction of the plant will start once SunEQ has obtained a generation license from the Electricity Control Board.
Jordan: LafargeHolcim’s Rashadiya cement plant is set to generate up to a quarter of its power from a solar plant that will start operations in July 2017. Dubai’s Adenium Energy Capital signed a deal for the cement producer to develop the photovoltaic (PV) facility, according to SeeNews. Previously the PV unit was reported to have a capacity of 15MW but this has not been confirmed. In October 2016 Adenium Energy Capital said it had commissioned four PV parks in Jordan with a total capacity of 50MW in total.