A practitioner of law approaching Europe’s energy sector today encounters something remarkable. Electricity trades in milliseconds and even carbon allowances flow with the liquidity of blue-chip equities. Quietly, yet profoundly, the energy market has assimilated the logic of the capital markets. Many analysts argue that systemic stability rests on two mutually reinforcing pillars, the financial system (banking, capital markets) and the energy system, and stress in either can cascade into the other with destabilising speed. The feedback loop that turns a liquidity squeeze into a blackout, or a fuel-price spike into a sell-off in utilities equities, is the essence of systemic risk. The convergence of these two worlds, energy and financial markets, has reshaped the compliance landscape. Energy transactions still involve the purchase or sale of a (in)tangible commodity. Financial transactions involve financial instruments whose value is detached from immediate physical delivery. Their interaction produces a hybrid marketplace in which every click on a trading screen can trigger two distinct, but increasingly overlapping, regulatory logics. Concurrently, the global turn toward sustainability, embodied in Environmental, Social and Governance (ESG) standards, obliges market participants to demonstrate transparent, credible adherence to decarbonisation goals, ethical conduct and social accountability across both their physical and financial operations. The aim of this thesis is to show how market participants can uphold both the letter and the spirit of these intertwined legal regimes, particularly REMIT, MiFID II, EMIR, and ESG-related frameworks. The thesis will first analyse the fundamentals of wholesale electricity trading, then proceed with a rule-by-rule examination of the core regulatory instruments, and finally explore the ESG criteria and their corresponding requirements.