The article literally states;
“An Indigenous-led coalition is fundraising to install solar panels along the route of TransCanada’s Keystone XL pipeline to protest the project and provide renewable energy to family farms and Native communities in Nebraska and South Dakota”
“We will not only build renewable energy in America’s breadbasket, on Indigenous lands for Indigenous people, demonstrating the goals of a just transition towards sustainable energy, but we will build it in the face of the Keystone XL pipeline.”
I believe that these Native Americans were in fact organizing specifically against the Keystone XL pipeline. Furthermore, even if they weren’t talking about just the Keystone XL my point applies to ALL petroleum projects in the USA. The fact remains that the USA does not use oil for electricity, which is the sole purpose of solar development. The US grid could be 100% solar and it would have zero effect on the petroleum industry (in fact it may even increase it as you would probably require diesel generators for backup storage).
If you want to create competition for oil then you have to support projects that transition the transportation industry and petrochemical industry not the electricity industry.