Waste heat recovery plant saves EOR operation 80% of electricity bill

Canadian oil sands producer Strathcona Resources has been able to offset up to about 80% of its current electricity grid consumption in an enhanced oil recovery (EOR) process with a new waste heat-to-power process based around an Organic Rankine Cycle (ORC) power plant.

The project, which has now been commissioned, is said to be the first waste heat-to-power project in a steam-assisted gravity drainage facility. That is a technique for extracting heavy crude oil and bitumen from deep underground deposits. It works by injecting steam into an upper horizontal well to heat the oil and reduce its viscosity; the heated oil and condensed steam then flow by gravity into a lower horizontal well, from which they are extracted.

The heart of the system consists of a 19 MW single-shaft ORC system, custom-designed by Turboden of Italy to recover low-grade heat (~150°C) from a mix of produced steam and non-condensable gas, previously dissipated to the atmosphere through aerial coolers.

The ORC system is a variation of the Rankine cycle, the thermodynamic process used in refrigeration, in which a fluid with a vapourisation temperature lower than water passes through stages of evaporation in a boiler and condensation in a heat exchanger, converting heat into work.

At the Orion facility in Cold Lake, Alberta, Canada, where it has been installed, the plant provides cooling, saves cost and provides site electricity.  

It was developed through a strategic collaboration between Strathcona, Turboden and the Federation Group, which served as the owner’s engineering, procurement and construction (EPC) partner for the project.

The facility has the capacity potential to offset 50,000 tCO₂e/y, and the company estimates it will save 740,000 tCO₂e over the facility’s lifetime.

Paolo Bertuzzi, CEO and Managing Director of Turboden, says: ‘Although Turboden has traditionally focused on renewable energy, we consider the optimisation of industrial processes – through efficient heat-to-power solutions – a key area to create value for the oil and gas sector while reducing carbon emission. We envisage several similar projects will follow.’

New wind turbine rotor design picks up light breezes

A new prototype design rotor for a low-power wind turbine is claimed to be 83% more efficient than comparable systems. It can generate 2.5 kW at a wind speed of 10 metres per second (m/s).  

The design is a collaboration between German construction firm BBF Gruppe and the Fraunhofer Institute for Applied Polymer Research (IAP).

Wind tunnel tests show that the rotor begins to turn at a wind speed of 2.7 m/s – said to be a key requirement for the efficient use of wind power in regions with low wind conditions. The starting speed for comparable systems is 4 m/s, according to IAP.

Marcello Ambrosio, Head of Simulation and Design in the Polymer Materials and Composite PYCO research division at Fraunhofer IAP says the project has optimised the aerodynamic design and the manufacturing process.

The rotor blades of the small wind turbine are constructed from two shells in a lightweight design. They are made of fibre-reinforced composite materials. Compared to conventional designs, which are constructed with a foam core, the newly developed components are hollow inside. This construction method reduces the overall weight up to 35%.

A special laminate structure also ensures that the rotor withstands strong winds. ‘We designed the individual layers of the composite material so that the rotor blades can flex elastically in a storm and turn out of the wind,’ explains Ambrosio. This automatically reduces the rotation speed of the turbine and protects it from overload. Complicated control technology and elaborate mechanics can thus be avoided.

Five prototypes of the small wind turbine were recently delivered to the BBF Gruppe to be installed at various locations. With this approach, the researchers and their development partner aim to find out how the position and height of the system affect performance.

Raúl Comesaña, Managing Director, BBF Gruppe, adds: ‘Efficient small wind turbines make an important contribution to an independent energy supply. As a project developer and construction company in the Berlin-Brandenburg region, we demonstrate with this project how end consumers and businesses can design decentralised energy generation individually and sustainably.’

Raúl Comesaña, Managing Director, BBF Gruppe (left) and Marcello Ambrosio, Head of Simulation and Design in the Polymer Materials and Composite PYCO research division at Fraunhofer IAP, in front of a prototype

Photo: BBF Gruppe  

Australian DC-AC battery wins A$25mn scale-up funding

An innovative design of battery that outputs AC without an inverter, which promises to improve the performance and cost-effectiveness of battery energy storage systems (BESS) used alongside renewable power, has won A$25mn ($16mn) of scale-up funding.

Batteries charge and discharge in direct current (DC), so to be moved elsewhere require an inverter to transform the electricity into alternating current (AC) that is used in transmission systems worldwide.

However, Melbourne, Australia-based firm Relectrify’s AC1 battery doesn’t require an inverter to output AC. Instead, it uses a proprietary battery management system (BMS) that controls each battery cell (of which there are nearly 4,000) to directly produce AC power. This design reduces battery degradation and can deliver 20% more energy over its lifetime, helping to lower energy storage costs, according to the Australian government’s Renewable Energy Agency (ARENA).

The ARENA funding follows earlier support of a project to reuse end-of-life batteries, and venture capital backing.

The funding will enable Relectrify to deploy up to 100 MWh of AC1 systems in the commercial, industrial and small front-of-meter markets.

Still from a video showing an animated exploded view of the AC1 battery

Source: Relectrify