Farmer in a field of Miscanthus at harvest time.
Monty Rakusen

Miscanthus is sometimes called elephant grass because of its height, growing to ten feet tall in a single season. The farmer in his field at harvest time.

Perennial Biomass Production

Support SinksLand SinksShift Agriculture Practices
CO2 Equivalent
Reduced / Sequestered
Billion $US
Net First Cost
(To Implement Solution)
Trillion $US
Lifetime Net
Operational Savings
Trillion $US
Net Profit
Bioenergy relies on biomass—often annual crops such as corn. Perennial plants (e.g., switchgrass, silvergrass, willow, eucalyptus) are a more sustainable source and sequester modest amounts of soil carbon.

Solution Summary*

Plant material is used in a variety of ways to create energy: combusted to produce heat or electricity; anaerobically digested to produce methane; and converted to ethanol, biodiesel, or hydrogenated vegetable oil for fuel. Within transportation, bioenergy makes up almost 3 percent of fuel consumed. Within the power sector, it comprises 2 percent of the total.

From a climate perspective, whether plant material used for bioenergy is annual or perennial (or waste content) makes all the difference. Because energy inputs for annual bioenergy crops, such as corn, are so high, they make little progress on cutting emissions.

Perennial bioenergy crops—such as switchgrass, fountain grasses, silver grass, poplar, willow, eucalyptus, and locust—can be different. Cultivated appropriately, they can reduce emissions by 85 percent compared to corn ethanol. Replacing annuals with perennials also raises carbon sequestration in soil.

Many perennial bioenergy crops are prime candidates to grow on degraded land not suited to food production. Compared to corn and other annuals, perennials can prevent erosion, produce more stable yields, be less vulnerable to pests, and support pollinators and biodiversity.

* excerpted from the book, Drawdown

Perennial biomass production provides the feedstock for biomass energy generation, making those emissions reductions possible. They also can generate their own climate impact of 4-7gigatons of carbon dioxide by 2050, as they replace annual feedstocks and sequester more soil carbon. Our analysis assumes a rise from 0.27 million hectares currently to 106-190million hectares by 2050. The cultivation of perennials is costlier than annuals with an establishment cost of $230-400and lifetime operational cost of $1.5-2.7 trillion but profits over lifetime could be $0.9-1.6 trillion.