Read impact on production database of dashboard refresh

I am using Grafana with the Postgres addon and a refresh period of 1h on a dashboard with about 20 panels, i.e. 20+ select queries.

Has anyone noticed degraded performance on Postgres caused by Grafana? I like Grafana and I am more concerned about scaling the number of dashboards and metrics and how to avoid spikes in the number of requests at times of the dashboard refresh.