Energy Management: From Conservation to Optimization and Sustainability

Reliable supplies of reasonably priced and environmentally friendly energy are essential for all manufacturing enterprises, as well as commercial and residential consumers. Yokogawa helps further these efforts by promoting efficient generation and use of energy worldwide. Our goal is to make meaningful contributions towards the realization of a society where everyone can easily access stable energy supplies at a reasonable price.

For large-scale process manufacturing plants—including refineries, petrochemical, and other chemical facilities—energy can easily account for 50% of operating expenses.

This fact, understandably, gives companies many reasons to reduce energy consumption and cost. Here are several questions some might ask as part of a savings effort:

1. Can we buy cheaper fuel? Low-sulfur fuel oil costs more than what we used to burn.

2. Can we upgrade our equipment to burn fuel more efficiently, and therefore use less fuel overall?

3. Can we modify our process to require less heat? Fewer BTUs per unit of production?

4. Are there other options for energy sources we should consider?

All of these could help, but they are in order of worst to best. Number one saves money (high sulfur petcoke is cheap) but ignores environmental effects. Numbers two and three are covered under the umbrella of traditional conservation efforts: find ways to use less energy. These are important, and virtually every facility that has been running for more than 10 years has undertaken a variety of programs to improve equipment performance and optimize processes to require as little energy as possible.

Number four begins to move into a more interesting area where there is a wider range of possible energy sources, especially renewables. Are there other sources of energy, available without environmental impacts? Can we get away from the idea that fossil fuels are invariably at the top of the list of selections? Companies that explore question four likely will go a step farther. 

5. How can we reduce our carbon footprint?

Companies that spend most of their effort on questions four and five have moved into the realm of energy management, energy use optimization, and sustainable development goals. These are overlapping areas with common characteristics reaching beyond conservation.

Management for sustainable society and manufacturing

A company pursuing this approach must follow an effective strategy, able to deliver the expected results. Such a strategy calls for a specialized set of digital tools combined with the right techniques. To describe this approach strategy, we’ll borrow a tool from the financial services industry.

Financial analysists looking at a company’s condition examine documents, such as the balance sheet and income statement. These are important, but a third statement provides deeper insights into day-to-day operation: sources and uses of cash. As the name suggests, it describes, in detail, where money comes from, and how it’s spent. Process manufacturers need to create their adaptation of this analysis: sources and uses of energy.

Sources: How does energy come into the plant? Electrical power from the local utility, natural gas, and fuel oils probably cover the list for most facilities, but it is important to drill into more detail.

For example, consider your electric power supply. Does your utility depend on coal-fired plants, or, less carbon-intensive sources such as wind turbines and photovoltaic arrays? Most will deliver a mix, but there can be some selectivity. Your own facility may have a cogeneration plant, but it’s impact will depend on the fuel source. Oil and natural gas maintain the fossil-fuel connection, but it can be mitigated by including flare gas, biomethane, and other sources of waste fuels. These can get you closer to supply optimization and net-zero emissions.

The challenge of renewable electric power is its availability. If the sun is shining and the wind is blowing while you can consume all the power generated, that’s fine, but you’ll probably need to have a storage mechanism to balance supply with demand. This can be in banks of batteries, manufacturing hydrogen via electrolysis when surplus power is available, flywheels, pumped hydro, or other energy storage systems.

Uses: Plants launching comprehensive energy analysis programs typically insert instruments into distribution systems to measure energy flow at a very granular level. This can include electric meters on electrical branch circuits to see where power is being consumed. Similarly, natural gas and fuel oil flows are metered at each consumption point, along with steam and compressed air. This is the first step to optimizing consumption.

The point where these efforts break down for most companies is linking the two sides. It isn’t easy connecting sources and uses with conventional analytical tools such as spreadsheets.

Yokogawa can provide comprehensive solutions to analyze energy supply, demand, and re-use through consulting services provided with deep domain knowledge and best-in-class digital technologies. It is possible and practical to identify areas where energy can be saved while increasing production, reducing maintenance, and improving availability.

This begins by identifying and eliminating wasteful energy use, which is possible using Yokogawa’s energy sensing technology to visualize the energy flow at each site, and for an enterprise as a whole. In addition, emission monitoring systems can help reduce pollution output and reduce environmental impacts.

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