Power control systems (PCSs) can exploit low-carbon technologies (LCTs) to provide grid ancillary services. This work develops a bilevel mixed-integer linear programming PCS of photovoltaics (PVs), electric vehicles (EVs), heat pumps (HPs), and battery energy storage systems (BESS), for providing automatic frequency restoration reserves (aFRR) with energy arbitrage, PV self-consumption, and customers’ thermal and charging comfort. The contribution of the BESS and the flexible loads is evaluated under different seasons, grid types and sizes, and energy/reserve prices. Validating against a PCS solely for minimum grid energy cost (energy arbitrage), the findings demonstrate the increased cost savings when a PCS participates in the reserve market with BESS and EV combined. The cost of solely energy arbitrage was found consistently higher than 100% (e.g., 40€ compared to only 19€ with aFRR provision). These benefits have become more important recently in 2023, with the higher energy prices, and much higher reserve prices compared to 2018 (up to 540% increase). While the always present BESS is able to contribute more to ancillary services compared to the uncertain EV fleets, the contribution of EVs increased to a notable 38.5% of the total provided aFRR energy share at larger grids. Finally, mixed nodes that comprise both residential-commercial buildings and home-public chargers have a higher potential for ancillary services provision, demonstrating a 5x and 12x higher potential compared to residential and commercial nodes, respectively. Overall, this work highlights the importance of PCSs in large grids or with a variety of loads to provide ancillary services for enhanced savings.