農場變能源

在能源轉型與農業減碳壓力同步升溫之際，美國農業正透過再生天然氣（RNG）與生質燃料技術，開啟一條結合環境效益與農民收益的新路徑。以紐約州乳牛農場為例，農民導入甲烷消化器（methane digesters），不僅有效降低碳排放，也創造額外收入來源，顯示農業部門正逐步成為低碳能源供應鏈的重要一環。

As the dual pressures of energy transition and agricultural decarbonization intensify, the U.S. farming sector is emerging as a key player in low-carbon energy supply chains through renewable natural gas (RNG)

在該案例中，農場將畜牧廢棄物輸送至由 LF Bioenergy 營運的設施，透過厭氧消化技術將有機物轉化為再生天然氣，並回收處理後的液體作為肥料再利用。此過程不僅減少甲烷逸散，也降低氣味問題，同時產出的生質氣體可直接輸送至天然氣管網，供住宅與商業使用，形成完整的循環經濟模式。

and biofuels. A dairy farm case in New York demonstrates how methane digesters can simultaneously reduce carbon emissions and generate additional income, signaling a structural shift in the role of agriculture.

根據 U.S. Environmental Protection Agency 預測，目前全美約2,500座再生天然氣設施，未來數年有望成長至十倍規模。這一擴張趨勢主要受惠於聯邦與州層級政策推動，包括 Inflation Reduction Act 等法案提供補助與稅收誘因，促進再生燃料進入市場。

In this case, livestock waste is transported to facilities operated by LF Bioenergy, where anaerobic digestion converts organic matter into renewable natural gas. The processed byproduct is returned as odor-reduced fertilizer, while the biogas is injected into pipelines for residential and commercial use, forming a closed-loop circular system.

除再生天然氣外，包含再生柴油、生質柴油、永續航空燃料（SAF）等替代燃料亦快速成長。

產業人士指出，美國再生柴油產量已在五年間從6億加侖擴增至40億加侖，顯示低碳燃料市場正進入快速擴張期。

According to the U.S. Environmental Protection Agency (EPA), the U.S. currently hosts around 2,500 RNG facilities, with projections pointing to a tenfold expansion in the coming years. This growth is largely driven by federal and state-level incentives, including the Inflation Reduction Act, which supports clean fuel deployment through subsidies and tax credits.

目前再生柴油與生質柴油合計已占美國道路柴油用量約10%，且仍持續提升。

Beyond RNG, alternative fuels such as renewable diesel, biodiesel and sustainable aviation fuel (SAF) are also scaling rapidly. Industry data shows renewable diesel production has surged from 600 million gallons to 4 billion gallons annually within five years. Combined, renewable diesel and biodiesel now account for approximately 10% of U.S. on-road diesel consumption, with further growth expected.

此趨勢對農業經濟帶來顯著影響。由於大豆油等農產品是生質燃料的重要原料，需求增加直接推升農產品價格與農民收益。例如，大豆油價值中約35%至40%回流至農民端，使農業不僅是糧食供應者，也成為能源轉型的重要供應來源。

This expansion is significantly impacting the agricultural economy. As feedstocks like soybean oil are essential inputs for biofuels, rising demand is directly boosting farm incomes. Farmers capture an estimated 35% to 40% of the value of soybean oil, reinforcing agriculture’s role as both a food and energy supplier.

專家指出，未來市場將更加重視碳強度（carbon intensity）較低的農產品。隨著企業加速減少範疇三（Scope 3）排放，生質燃料業者可能以溢價收購低碳農作物，以符合減碳標準並取得政策補助，為農民創造更高附加價值。

Looking ahead, markets are expected to increasingly prioritize low carbon intensity feedstocks. As corporations work to reduce Scope 3 emissions, biofuel producers may offer premiums for sustainably produced crops to meet regulatory standards and qualify for incentives, creating new revenue opportunities for farmers.

整體而言，再生燃料的發展不僅有助於減碳與能源轉型，也重塑農業角色，使其從傳統生產端，轉型為結合環境、能源與經濟價值的關鍵產業。然而，最終市場規模仍將取決於政策穩定性、國際需求與能源轉型進程。

Overall, the rise of renewable fuels is not only advancing decarbonization but also redefining agriculture as a central pillar of the clean energy economy. However, the long-term trajectory will depend on policy stability, global demand and the pace of the broader energy transition.