Regarding your question, the method of grounding your solar panels will depend on the specific requirements and regulations of your area. However, it's common for solar panels to be grounded both to the power utility ground in the box as well as a spike outside in the ground.
If you have concerns about the grounding of your panels, it's always a good idea to consult with a licensed electrician or solar panel installer who can assess the installation and ensure that everything is done according to the necessary standards.
In terms of fixed energy tariffs, there are many companies in the UK that offer this type of plan. Fixed energy tariffs are beneficial because they provide a stable price for your energy usage, which can help you budget your monthly expenses more effectively. Some popular energy providers in the UK that offer fixed tariffs include EDF Energy, ScottishPower, and British Gas.
I hope this information helps! If you have any further questions or concerns, please don't hesitate to reach out to me.