Wind turbines power off-grid sites
By Del Williams
When considering off-grid, renewable sources of energy to power sensors, meters, pumps, controllers and communication links at remote industrial sites, the options typically come down to two: solar or wind.
Solar, an inexpensive option, is often selected. However, with the availability and decreasing cost of small, off-grid wind turbines that operate in even modest wind conditions, the better answer is now both.
Hybrid systems that incorporate both solar panels and wind turbines, it turns out, form a perfect complementary relationship with each compensating for the weaknesses of the other system. Where solar is best during the daytime, wind power works throughout the night. Where solar is better through the summer months, wind power is better in winter months. And, on stormy and overcast days, wind power is the only option for generating power.
Cost effective equipment
Maintaining continuous, reliable power at remote, off-grid substations is a critical concern in industries ranging from oil and gas to telecom, and mining to railroad. If power is lost, key measurement and monitoring equipment along with data communications can lead to production shutdowns, which may cost a company thousands per hour in some cases.
“An unplanned power outage can cost tens of thousands of dollars in lost production and unscheduled downtime,” says Tony Kaspari, an electrical engineer at Beabout Co., which consults with industrial companies, such as oil and gas, water-wastewater, and electric utilities in the Rocky Mountain area.
Some of the early adopters of this hybrid wind and solar technology include oil and gas titans Marathon Oil and Hilcorp.
Marathon Oil, the Houston, Texas, based energy behemoth, has operations on four continents, while Hilcorp, also a Houston based energy giant, has operations spread out across North America and the Gulf Coast. Both have found the hybrid wind turbines and solar systems allow for operations in areas that would have been near impossible 10 years ago.
“Without continuous remote data, oil and gas producers for example, might have to shut down production to ensure safety,” Kaspari says. “Integrating a $1,000 wind turbine with a new or existing solar power system can ensure that production stays online even during adverse weather conditions.”
While the power demands at some of these off-grid industrial sites and substations may not be large, connecting them to the grid is simply cost prohibitive.
“Since it can cost anywhere from $80,000 to $100,000 per mile to run power poles or lay underground power cables to a remote site, it doesn’t make sense to run power for small power requirements,” says Brent Busenlehner, president of ReadyFlo Systems, a Corpus Christi, Texas, based system integrator of remote power systems, automated control systems, and integrated measurement/production equipment.
Wind and solar combined
Solar power, though relatively inexpensive, is not always as reliable as advertised when paired with batteries for power storage. To generate power, solar panels must collect sunshine at sufficient intensity and at the right angle. This does not occur at night, when it is cloudy, overcast, and throughout much of the winter. If snow covers the panels, power is not generated until the snow melts or the solar panels are cleaned off.
“Remote power systems need to be designed for the worst case scenario, which is typically in the dead of winter,” says Busenlehner. “In winter, there is only an average of 4-4.5 hours of sun per day in South Texas, and only three hours of sun per day in the Dakotas, according to the Department of Energy. In the worst case, there is no sun for potentially long periods of time.”
Wind power complements solar power because it often produces the most power precisely when solar power is reduced or unavailable, such as at night, in inclement weather, and during winter. Wind often blows during long winter nights and is, on average, actually stronger in inclement weather. During winter, average wind speed is highest, as is air density, both factors that contribute to wind generating more power when solar power tends to be least available.
To enhance power reliability and build in redundancy, many off-grid industrial substations are now being retrofitted with small, off-grid wind turbines from leading suppliers such as Primus Wind Power.
Available in several models for areas with different wind speeds and climates, the small wind turbines are designed to generate power at wind speeds as low as 6 mph, and can generate as much as 40 to 80 kWh a month per turbine depending on conditions. Each turbine measures about four feet in diameter, weighs about 13 pounds, and costs about $1,000 per unit.
A single wind turbine is able to power to several devices. If more power is required, several turbines can be combined together. Far from a new concept, Primus alone has already installed more than 150,000 small off-grid turbines with units currently operating worldwide.
“If your industrial process or paycheck depends on having reliable remote power, then you need to look into adding a Primus wind turbine to your existing solar only system, or integrate it from scratch,” says Busenlehner. “At a minimum, with wind power you will have some power generated nearly every night when there will be zero solar energy to harvest. The combination extends system capacity and makes the worst case scenario, a power outage, unlikely.”
Another benefit of adding wind power to a solar powered system is that it lengthens battery life by reducing the depth and frequency of discharge. Since off-grid industrial devices or substations are powered by wind when solar power is unavailable, this avoids drawing down the system’s batteries and increases battery life significantly.
“Adding wind turbine power to a solar energy system could potentially double battery life because the batteries won’t discharge as deeply” says Busenlehner. “Extending battery life reduces system maintenance and replacement costs, and the savings can be significant.”
According to Busenlehner, it is relatively easy to retrofit a remote, off-grid site powered by solar only. “… it is as simple as wiring the leads from the turbine to the batteries and adding some fuses, switches, and amp meters for equipment protection,” he says. “It’s even easier to integrate solar and wind power into a brand new system.”
Carbon dioxide removal revenues worth £2bn a year by 2030
Carbon dioxide removal revenues could reach £2bn a year by 2030 in the UK with costs per megatonne totalling up to £400 million, according to the National Infrastructure Commission.
Engineered greenhouse gas removals will become "a major new infrastructure sector" in the coming decades - although costs are uncertain given removal technologies are in their infancy - and revenues could match that of the UK’s water sector by 2050. The Commission’s analysis suggests engineered removals technologies need to have capacity to remove five to ten megatonnes of carbon dioxide no later than 2030, and between 40 and 100 megatonnes by 2050.
The Commission states technologies fit into two categories: extracting carbon dioxide directly out of the air; and bioenergy with carbon capture technology – processing biomass to recapture carbon dioxide absorbed as the fuel grew. In both cases, the captured CO2 is then stored permanently out of the atmosphere, typically under the seabed.
The report sets out how the engineered removal and storage of carbon dioxide offers the most realistic way to mitigate the final slice of emissions expected to remain by the 2040s from sources that don’t currently have a decarbonisation solution, like aviation and agriculture.
It stresses that the potential of these technologies is “not an excuse to delay necessary action elsewhere” and cannot replace efforts to reduce emissions from sectors like road transport or power, where removals would be a more expensive alternative.
The critical role these technologies will play in meeting climate targets means government must rapidly kick start the sector so that it becomes viable by the 2030s, according to the report, which was commissioned by government in November 2020.
Early movement by the UK to develop the expertise and capacity in greenhouse gas removal technologies could create a comparative advantage, with the prospect of other countries needing to procure the knowledge and skills the UK develops.
The Commission recommends that government should support the development of this new sector in the short term with policies that drive delivery of these technologies and create demand through obligations on polluting industries, which will over time enable a competitive market to develop. Robust independent regulation must also be put in place from the start to help build public and investor confidence.
While the burden of these costs could be shared by different parts of industries required to pay for removals or in part shared with government, the report acknowledges that, over the longer term, the aim should be to have polluting sectors pay for removals they need to reach carbon targets.
Polluting industries are likely to pass a proportion of the costs onto consumers. While those with bigger household expenditures will pay more than those on lower incomes, the report underlines that government will need to identify ways of protecting vulnerable consumers and to decide where in relevant industry supply chains the costs should fall.
Chair of the National Infrastructure Commission, Sir John Armitt, said taking steps to clean our air is something we’re going to have to get used to, just as we already manage our wastewater and household refuse.
"While engineered removals will not be everyone’s favourite device in the toolkit, they are there for the hardest jobs. And in the overall project of mitigating our impact on the planet for the sake of generations to come, we need every tool we can find," he said.
“But to get close to having the sector operating where and when we need it to, the government needs to get ahead of the game now. The adaptive approach to market building we recommend will create the best environment for emerging technologies to develop quickly and show their worth, avoiding the need for government to pick winners. We know from the dramatic fall in the cost of renewables that this approach works and we must apply the lessons learned to this novel, but necessary, technology.”
The Intergovernmental Panel on Climate Change and International Energy Agency estimate a global capacity for engineered removals of 2,000 to 16,000 megatonnes of carbon dioxide each year by 2050 will be needed in order to meet global reduction targets.
Yesterday Summit Carbon Solutions received "a strategic investment" from John Deere to advance a major CCUS project (click here). The project will accelerate decarbonisation efforts across the agriculture industry by enabling the production of low carbon ethanol, resulting in the production of more sustainable food, feed, and fuel. Summit Carbon Solutions has partnered with 31 biorefineries across the Midwest United States to capture and permanently sequester their CO2 emissions.
Cory Reed, President, Agriculture & Turf Division of John Deere, said: "Carbon neutral ethanol would have a positive impact on the environment and bolster the long-term sustainability of the agriculture industry. The work Summit Carbon Solutions is doing will be critical in delivering on these goals."
McKinsey highlights a number of CCUS methods which can drive CO2 to net zero:
- Today’s leader: Enhanced oil recovery Among CO2 uses by industry, enhanced oil recovery leads the field. It accounts for around 90 percent of all CO2 usage today
- Cementing in CO2 for the ages New processes could lock up CO2 permanently in concrete, “storing” CO2 in buildings, sidewalks, or anywhere else concrete is used
- Carbon neutral fuel for jets Technically, CO2 could be used to create virtually any type of fuel. Through a chemical reaction, CO2 captured from industry can be combined with hydrogen to create synthetic gasoline, jet fuel, and diesel
- Capturing CO2 from ambient air - anywhere Direct air capture (DAC) could push CO2 emissions into negative territory in a big way
- The biomass-energy cycle: CO2 neutral or even negative Bioenergy with carbon capture and storage relies on nature to remove CO2 from the atmosphere for use elsewhere