Following the Paris agreement, many nations have committed to targets of net zero emissions, resulting in a significant increase in low-carbon energy generation. Recent improvements in the cost and efficiency of photovoltaic (PV) technology has made it highly competitive, with the uptake of PV projected to surpass fossil fuels by 2035. Large-scale, ground-mounted solar parks are likely to constitute a considerable portion of this expansion. Despite the expansion of solar parks and the associated land use change, there is very little understanding of the environmental implications. In particular, the effect on ecosystem carbon cycling, and thus the decarbonisation attraction of the technology, is unknown. Here, we complete a systematic review of existing renewable energy carbon calculators, identifying carbon stocks and flows during construction, operational and decommissioning life-cycle phases. This insight is used to develop an idealised solar park carbon calculator (SPCC) that quantifies the full suite of solar park technological and ecological carbon impacts. We determine the carbon stocks and flows for solar parks drawing on established quantifications for system components, operation, and land management. Key components include the emissions factors for production of panels and mounts, machinery related emissions and the associated carbon flows of ground disturbances, before and after park construction. Carbon emissions offset by replacing grid mix electricity with that generated by the solar park are also included to provide an estimate of carbon payback time. Recommendations are provided as to how carbon payback time can be reduced, including manufacturing components with low-carbon energy, and avoiding placement on areas of high ecosystem carbon (e.g., peatlands). Finally, critical knowledge gaps, uncertainties and future options for development are outlined. The SPCC can help inform solar park developer decisions in order to minimise carbon costs and maximise carbon sequestration, ultimately helping to meet net zero goals.